Well, I’ve been meaning to upgrade to MoveableType 3.x for about two months now. Oh a whim, I just went and did it tonight. No problems.
Well, the heart failure when I couldn’t log in. But besides that, nothing.
And if you upgrade, make sure to run the upgrade scripts after uploading the files. Just uploading isn’t enough. You really ought to run the scripts, as well.
Because, well, if you don’t run them…you can’t even log in.
Let me know if you see anything amiss.