As a complement to the other thread highlighting Cydia apps that won't work, I thought it'd be helpful to document Cydia apps that are working with 3.0. Please add as you discover working apps.
iBlacklist seems to be working perfect
iRealSMS, from their beta repo, works but acts a little glitchy in the settings windows.
SBSettings works 99.9% -- however, the free memory number doesn't update when memory is freed up. Memory is freed, it's just not represented accurately on the bar across the top of the screen until you launch an app.