I'm running it right now, reading this. Started right up with only one caveat. I have (had) KeyWurl installed and it told me it wouldn't load it as a precaution (I think it mentioned SIMBL in the message).
Otherwise it's running flawlessly. I was expecting problems after reading the Ars article but nope, none.
Interestingly, WebKit now looks just like Safari 4. I usually run WebKit and Minefield, not Safari but I thought I'd give it a shot. It's pretty nice.
