Based on the current leaked build of SL, it seems that QuickTime X is far better than the standard QuickTime 7, but still lacks some of the features that were in QuickTime Pro. It gains some former Pro-only features like being able to save for the web, or exporting to other formats like the iPhone. Thus, I think Apple is going to be discontinuing QuickTime Pro (because honestly, it was so easy to pirate, who would spend $29 on it?) and will simply add more former Pro-only features as updates to SL are imminent. Also, for those curious, at the moment, it doesn't seem to support any more codecs than the current QT does. I still can't play .wmv, .avi or .mkv without the help of Perian.