I'm a few months off 20 but I feel the need to comment. After 20 (or just high school really) playing a lot less of a big deal than if, say, you're 15 and entering high school where people are malicious.
Most girls who would actually accept pokemon players are girls who go to comic book and gaming conventions.
This is so ridiculously false. Everytime I meet a new girl and she asks me about my hobbies, I always bring up pokemon. This usually results in a funny look yes, but the fact never ruins any chance with them. I simply say I do some battling in my free time and move on with the conversation (I never open or close the topic with pokemon). You're not required to bring it up of course, but point is pokemon in and of itself is never (emphasis never) an instant bye with women; if you've got selling points they won't care. (btw there's nothing wrong with a good gamer girl)
As zerowing said friends might rag on you but it's all in good spirit (girlfriends do to :P). And then as Chou said, acquaintances really won't care. Assholes that do try to give you beef over it will find a reason to bother you regardless.
I really do not understand the big conniption with letting others know you play pokemon. Maybe it helps that I don't spend hours breeding pokemon and trying to work an RNG to run a virtual store, but honestly as long as you're not obsessed and/or going to great lengths to defend yourself over it, nobody will care. Obviously don't bring it up at every opportunity or go out of your way to inform everybody, but don't go to lengths to cover it up. The world won't end if somebody finds a Platinum version in your bag. If they ask you if you play pokemon, say "Yeah, so?" Guarantee it never comes up again (not because it's awkward either, but, again, they don't care). You're not judged for every little thing you do.
EDIT: Let me put it this way: significantly more women are going to be turned off by you playing Halo or Call of Duty than Pokemon.