Hey, don't think that there won't be suits in the future that help people perform amazing feats. The army has ordered such a suit from some uber secret scientists =)
Also, don't forget cybernetic implants...
Part of the coolness of sci-fi is realistic type stuffs, like you mentioned. But the other cool part about sci-fi is that it has no rules, no borders, no boundries. Sci-Fi is whatever your brain makes up. And granted, some of it is stupid (Star Trek), but some of it is also very very good (BladeRunner, Terminator, Predator, The Matrix, 12 Monkeys, Mystery Science Theater 3000, books by Larry Niven and Jerry Pournell, Jack Vance, Robert A. Heinlein, Isaac Asimov, Orson Scott Card). Thank heaven Sci-Fi isn't bound by the limits that YOU set for it. If it were, we would've missed out on a lot of cool stuff.