I am a E-10 user who is very happy with this camera for my personal use.
You don't say for what sort of photography you want to use this camera. The E-xx is best suited for a more deliberate work style. Because the buffer only holds 4 shots, action is not its forte (although do-able). The 5 meg E-20 takes longer to clear the buffer than the 4 meg E-10; to me, the latter's time is only marginally acceptable. Also, noise at higher ISO's is a problem.
On the other hand, it is very quiet in operation (no flipping mirror), has quick shutter response and fits well in my hand. The LCD in back also flips out so you can use it to compose your shot from overhead or a very low angle. And there's no sensor dust problem!
Check out DPReview's Olympus SLR forum for some who use this camera professionally. They may be better able to help you. I'd also keep my eyes open for PMA announcements.
While the new Canon 10D is very tempting, I think I will keep using the E-10 while I wait for a full-frame DSLR affordable by us mere mortals. Or unless I should win the lotto, whichever comes first [g].
If you have any other questions, I'll be glad to help.