It's easier than you think to avoid the pink and blue paradigm. Here are some sources for baby clothing that sends a message. Often a message that someone, somewhere, in a mall near you, will find deeply offensive.
Dookiewear.com wants to dress "your cool little punk" in sweatshirts, hoodies, t-shirts, and rompers (the non-trademarked version of a OnesieĈ , I guess.) printed with slogans like "bad ass baby," "already a feminist," and variations on "my mom's tattoos are better than your mom's." In fact, a lot of their designs include tattoo art. Rocker tattoo art.
Hot Topic, meanwhile, is "a mall-based chain of retail stores that specializes in apparel, accessories, gifts, and music for teenagers." And their kids, I guess.
They have an Insane Clown Posse t-shirt, for example, for when your kid beats the crap out of that Benetton-wearing wuss in the sandbox.
If Insane Clown Posse isn't polarizing enough for you, there's one more place you can shop: just two-step your way over to the George W. Bush Online Store and get yourself somethin' nice, like a Bush/Cheney '04 bib or romper. It's a shrewd merchandising move that leaves no child behind; supporters will derive sheer joy from indoctrinating their youth early, and haters can enjoy watching their kid poo and spit up all over their nemesis. No profits to charity.