There have been some reports before how Flash is not working so flawlessly on smartphones, and now people say that it's not too great on the Galaxy Tab, either. I believe them because I don't think the processing power we have in phones in tablets right now is enough to play Flash smoothly on any occasion. Plus, Flash is not yet hardware accelerated on any of these chips found in smartphones today. So that definitely doesn't help either. Tegra 2 promises hardware acceleration for Flash, and it's also a dual core CPU, so we might see a lot less problems for Flash once dual core chips are here.
The problem still remains that Flash doesn't seem to be such a great piece of software. On my laptop it crashes Chrome at least once per day for me, and it's the only reason Chrome crashes for me. So even though we have Flash available on Android right now, I think we should look at it simply as a way to get us by until we have more HTML5 stuff around that will almost completely replace Flash.