There's something that you'll learn, and probably very quickly... No one wants to work like they're being paid on only the promise of money after the game is released.
That's not so much that people inherently don't have faith in an idea (though sometimes that's the case), more that anyone who's been in the development scene for a while knows that so many games just don't get off the ground, no matter how hard working or good or independant the team is.
You also have to remember that you're not offering an amazing experience and resume piece to people, they're offering to help you get out of having poor art on your project. And that's fine, but don't act as if it's anything else.
That may sound negative, but it's just how it is for the former and how it comes across for the latter.
Being more positive about this, the way to fix this is simply saying "No payment". It prevents you seeming unreliable, or at fault if the game flops or never gets released, and it prevents you being able to take advantage of the artists by spouting bullhockey about higher pay in the future or whatever (though you sound like you wouldn't anyways, but try to think of it from the perspective of the person working for free). Also less legal documents and contracts this way! Which you should definitely be writing up if you're serious. ;)
Additionally, you can't recruit here-- Go post over at http://www.gamedev.net/classifieds/category/5-hobbyist-projects/. Yes, hobbyist. I know you have the desire to get it out commercially, but you're also not paying.
Probably also a good idea to go over the vague ideas in the game to make any artists willing to devote their time more interested in picking it up as sort of a personal project. What genre is it? Do they have the freedom to develop the art style or do you already have something in mind and just can't draw it yourself? Isometric, sidescroller, top down...? They'll be more likely to look into if what you're describing sounds interesting to them, and like something they know they'll either have fun with or do without much time or hassle put into it.
Also would be nice if you could post your portfolio (this is my sly way of telling your to start making one now if you haven't) and/or previous games you've documented or progammed on. If you have a notable function, script or base for something you've done, show it, so the artists know you can follow through, and maybe even end up with a playable prototype with their art in it that they can show on their portfolios (that's a pretty good no-money payment, btw, as long as you can follow through).
Good luck, hope you can find some artists who'll help you out!