The Transformer Prime is really attractive to me right now but at $600+ with the keyboard dock its just too expensive for a marginal improvement over my A500.
I will continue to look towards Asus when I consider my next tablet - probably around x-mas 2012 or spring 2013 - they certainly seem to be the leader in the Android Tab segment.
With the upcoming Google Tablet, the recent release of iPad3, and the upcoming release of ARM based Windoze 8 tablets I expect all Android tabs to come down in price by ~100 for Xmas this year. If I could purchase the low end Transformer prime with the keyboard dock for around 400 that might persuade me.
Perhaps I would wait as long as summer 2013 for a much improved Transformer Prime shipping with Jellybean, a higher resolution screen and faster hardware.