Black - it just looks better IMO - classy...
As far as the comments about the white "getting dirty"... the actual color (black OR white) is under the glass... It's not like it's one of the older white MAC laptops, desktops or iPods, where those units were encased in a white plastic exterior casing. The design of the iPad puts the border color under the actual glass screen, so it will never get discolored or dirty.
Color is just a matter of owner preference when factually speaking, since on these devices, it cannot become dirty. (oh yea, same holds true for the white iPhones too...)
As far as the comments about the white "getting dirty"... the actual color (black OR white) is under the glass... It's not like it's one of the older white MAC laptops, desktops or iPods, where those units were encased in a white plastic exterior casing. The design of the iPad puts the border color under the actual glass screen, so it will never get discolored or dirty.
Color is just a matter of owner preference when factually speaking, since on these devices, it cannot become dirty. (oh yea, same holds true for the white iPhones too...)