The hardware itself. I'm not a fan of the new plastic case, especially after seeing forum post complaining of cracks/creaks. The screen now seems dwarfed in the centre because the case is slightly bigger, which makes the phone look like the hunchback of notre-dame. Speaking of the screen...it's now Jaundiced (yellow) which would bug the hell out of me
Feature wise there hasn't been much change, camera still sucks, BT still sucks, *insert tons of other missing features*...only 3G/GPS both of which i can live without especially with the spotty coverage and lack of turn by turn functions or pedestrian mapping.
Also, if i were to indulge my elitist side, EVERYONE now has one...but this is a minor reason cause i don't care that much
Finally 2.0 software is also available for the original iPhone which further reduces all probable incentives
Begs the question do i really want to lock myself into an 18 month contract for just 2 new questionable features...my answer was...nope!