Given how long we waited for the Windows Mobile 6 download for the BlackJack, we were tempted to mostly ignore the Byzantine instructions for installing the update. Fortunately, we didn't - and neither should you.
After just a few hours of use we can say that this definitely feels better than the leaked ROM. This new ROM is build 179188.8.131.52, up a few ticks from the leaked 177184.108.40.206 - so we're confident that the delays were genuinely caused by bugfixes and not by AT&T trying to force us to upgrade to the BlackJack II. ...Pretty confident. ...Sorta confident.
In any case, the Windows Mobile 6 update for the BlackJack brings the little guy up to date -- for my money it's the best deal out there for a Windows Mobile device these days.