My only regret with getting a white 4S is that it's difficult to find a matching case that doesn't look odd. Bumpers are OK, but they don't offer me the protection that I need.
Also, despite the fact that the iPhone 4/4S design is indeed beautiful (hats of to Mr Ive here), the white version just can't match the understated elegance of the black. It's flashy, but not "classy" if you know what I mean?
That being said, I do actually like the white version, it feels very fresh after nothing but black iPhones since 2009