I wrote about Evolution 0.2 last summer, when it was barely out of the larval stage. While some serious progress has been made between 0.2 and the current 0.8 release, there is still work to be done before 1.0 goes out the door later this year. The biggest difference is that I can now use Evolution in my everyday life. It still crashes and you should still back up your mail folders, but I'm using it now for two POP accounts, calendaring, and contact information.
Evolution is still very attractive.
It still operates out of the same basic framework and looks like it will become the premier mail client for Linux. And it is still a work in progress. I don't recommend throwing away your current mail client and moving to Evolution today. If you're not quite ready for mail on the edge, you might think about switching later. It's going to be a dandy.