I use an Olympus E-1 and I have to say I really like it. For the dusty dirty areas I shoot in, the weather sealing and dustbuster really works. I am a klutz and I promise, me cleaning a sensor would spell disaster. After 10k shots, many in a very very dusty barn, I don't have dust on my sensor(I check with F22 sky shots)

I really wanted the weather sealing but couldn't justify/afford/carry the Pro series Nikon/Canon cameras

I love the Zuiko glass. I will probably buy the next E-X after it comes out. I do hope to see improved AF and High ISO performance. Canon smokes Oly there. Those are rarely issues for me. But, it would be nice to have it