I used to have a lot of extropians in my social circle, and through conversations with them I arrived at a position that I jokingly referred to as "weak anthropic extropianism". Simply put, it is my opinion that while the chances of my surviving to an advanced age are quite high, and our understanding of biology, genetics and aging is advancing so fast that younger generations -- possibly even people who are alive now -- may in fact be able to extend their lives indefinitely, the question of whether I as an almost-34-year-old Western woman will have that option is already settled. Either I was born late enough to take advantage of the fruits of research into Not Dying, or I will die before this option becomes available to me. Realistically, it's probably the latter, and so I live every day with a subtle awareness of my own mortality. It's an interesting motivator: some day, you will die, and there's a lot you want to accomplish before that happens, so hop to it! Thinking about time and effort as finite resources also helps me to recognise sunk-cost fallacies, which is a nice cognitive benefit. All in all, it may not be optimistic, but at least it's adaptive.
Support for the weak anthropic extropian position comes from a variety of directions. These graphs of how cancer survival rates have improved over a period of 43 years show how dramatically and consistently the evidence-based approach with which we investigate disease has produced results in the form of living, cancer-free human beings. "Personalised medicine" is starting to become a reality; already, millions of patients are treated for rheumatoid arthritis or Crohn's disease with monoclonal antibodies, designed to inhibit an immune-system protein which their bodies have problems with. Monoclonal vaccines and other anti-infectives -- proteins tailored to knock out specific viruses -- are on the market already. Customised therapies are a pretty short bridge from there. It'll start with some weird fucking disease, probably an autoimmune disorder because that's where the Westerners are when you draw your map by morbidities, though I wouldn't be at all surprised if AIDS research heads in the direction of tailoring different therapies to different strains of the virus -- and then, armed with the discoveries in genetics (and more importantly, genetic engineering) from that endeavour, tailoring them to patients as well.
Put another way, I think we're going to find out whether it's possible for there to be a non-physically-aging Homo sapiens pretty soon now, whatever the answer actually ends up being.
But, you know, an awful lot of alchemists probably said "I think we're going to find out whether it's possible to transmute lead into gold pretty soon now, whatever the answer actually ends up being" not too long before the discipline of alchemy underwent a phase transition into the discipline of chemistry (with significant help, I might add, from the disciplines of brewing and, I shit you not, accounting. The taxation of alcohol plays an enormous role in the history of chemical engineering.) The good parts of alchemy (a lot of the equipment that was developed, and a lot of practical knowledge about things like melting and boiling points, as well as ways of keeping records of experimentation) provided a springboard for the development of a far more accurate and predictive model of the properties of natural (and, later, unnatural) substances. So even if the answer really is "no, aging is inescapable," we're going to learn -- have already learned -- a hell of a lot about how the human body works, and how it can break, and how to fix it when it breaks, and that's the kind of knowledge that can be employed to help make sure that billions of mortal human beings experience a healthier and more enjoyable ephemeral, all-too-short existence.
This position is inherently futurist, though not as dramatically so as strains of futurism that focus on climactic achievements of great technological depth. An imagined future where some people never age is the stuff of science fiction; same for one where brain-computer interfaces exist. The goals that I as a weak anthropic futurist am interested in accomplishing are ones of great scope. How can we wipe out nutrient deficiency diseases in the developing world (and among the poor in the developed world)? How can we dramatically reduce the attack surfaces of network protocols? These are things that affect people right now, and they're problems I happen to be interested in solving and think I stand a reasonably good chance at being able to affect in a positive way. So that's why I don't make an effort to hang out with the H+ crowd. I think they're great folks, I drink beer with them at conferences, I love what they're doing, I'm just working on different stuff. Your brain-computer interface is going to need protocol implementations that don't have parser vulnerabilities, for crying out loud, so Imma make sure you guys have the tools to do that, particularly since it helps out the Internet we already have.
Human health (and network health) are big problems. Billions of people, billions of computers. And one thing we've learned in the last several decades is that large-scale systems are a field of study in themselves. Sometimes people try to build predictive models of large-scale systems, and usually, when they fuck it up amazingly, everyone knows that something got amazingly fucked up (cf. the failure of predictive models that led directly to the credit crisis) even if they don't know which model failed. I don't think we really notice when predictive models -- like the one at the power plant that feeds your city, which predicts how much demand to expect and takes generating capacity on- and off-line to avoid waste or damage -- succeed. Large-scale engineering works; the very existence of the Internet provides all kind of fascinating case studies. I think we will derive tremendous increases of human health and happiness from better understanding of how these sorts of systems do -- or don't -- expand or contract, thrive or perish, succeed or fail as platforms for whatever we try to launch from them. Evgeny Morozov, for instance, levies a lot of criticism at "techno-utopians" who advocate spreading freedom through spreading free speech online, and Malcolm Gladwell derides "Facebook activists"; both are often perceived as gadflies, but they provide a vital service, looking for feedback that shows whether a certain large-scale behaviour produces a desired outcome or not. (Gladwell less so than Morozov, as Gladwell's target is really a strawman.) So I suppose you could say that if I'm a futurist, then my futurism is directed toward problems of scale with regard to health and information processing.
Or I could just say "yeah, I think it'd be really awesome if everyone never got sick and always had safe, reliable ways to communicate and access information from anywhere in the world, and I think we can achieve these things, so let's hurry up and make it happen already!" That probably sounds more mainstream-futurist.