If you can run Maya 7 then 8 will be the same. Personally I would not change. Why fork out the money to go to 8 when there are very little advantages or advances from 7 to 8.

Stay with 7, I have played with 8 and the menus got me and it has a bit of a max feel to it at first when creating geometry, until you change the settings that is. The menus are renamed and reampped to be different. I didn't like it I have used Maya 6/6.5 and 7 and I will be staying with 7.