I just bought the game and now it says on Upcoming that they're reprinting it. Is it just going to be something small like cleaner rules?

I'm pretty sure it just means that they sold out of the first printing and need to make more.  If there are any changes from the first printing they will likely just be corrections of typos.

Hm. Well that's certainly annoying but I guess it could've been worse

I fail to see how one could be annoyed that Cosmic is getting a reprint.  Sounds like wonderful news to me.  If it did well enough to deserver a reprint, they are likely putting a lot of effort into the expansion and probably planning more expansions in order to get the most out of their product.  The reprint will likely include the FAQ (either separately or better yet integrated into the rules).  If it included anything new, that would be annoying.  That would be redundant.  I don't want to have to repurchase the entire product for something new.  That's what expansions are for.  

And a reprint will allow others to get their hands on the game  I missed it on the first print and I missed it when GW produced it all those years ago!