An iPhone a developer with over 40 apps to his credit wrote to tell me about some major problems that have been afflicting the App Store for a week.
The sort by "Release Date" on iPhone and iPods isn't working, but it is on iTunes. Many developers have been calling Apple to complain but the problem still isn't fixed. Most developers are finding that when they get an app approved for update, or a brand new app, it's not appearing in the App Store at all.
There was also a huge thread about this on Apple's Developer forums beta but those are down right now since the 3.0 release.