There's nothing wrong with jaolbreaking an iPhone, but I've read too many posting about the troubles it causes. Nevertheless, I'd probably jailbreak too if my phone didn't work so darn well now!
Oh ok, I havnt had any problems as of yet and I jb my iPhone 4 2 days after I got it (and I got it on launch day) so hopefully I won't run into any problems, eithwer way if you do run into problems with a jail broken device you can always restore