All these “what tablet?” arguments are IMO the same as all the “what new phone?” debates. Apple’s technology (again IMO) is made all the better because of the App Store, hence why the iP4 is “better” and “more useful” than possibly any other phone out there.
The same for tablets … loads of cheap imitations and nothing really from the Android stable that rivals Apple.
So as someone that has an iP4, MBP, laptop and PC, do I really need another device? Well, I’m a sucker for “stuff that looks pretty” and can see us forking out for an iPad2 before the year is it. We don’t need one, but it sure as hell is one foxy piece of kit.
EDIT: no retina is a thumbs down though. iP4 literally opens your eyes to what’s possible (compared to the competition).