About two months ago, I detailed my expectations about iPhone OS 3.0 on my personal blog, and I still stand by what I said. I suspect the focus on 3.0 to be the introduction of new features such as a copy-and-paste, push notifications, enterprise management, and application management. I think the atrocities such as lack of MMS, lack of Flash, missing landscape views throughout the OS and wireless syncing are all simple enough features that could easily have been introduced as point release to the 2.x series.
The only real clue we have with the new iPhone is the fact that there will be a new SDK. This suggests that we will see new functionality in the APIs, which further suggests additional capabilities rather than mere bug fixes.
Whatever the case, it seems likely that Apple is going to step up their game in the face of also-rans, such as the LG Voyager and the Blackberry Storm, and possible competitors like Android powered phones the forthcoming Palm Pre. It would be hard for anyone to argue that Apple hasn't changed the smartphone game; many are hoping that firmware 3.0 is as revolutionary as its predecessors.