The leaked ROM was taken off of the forum where I found it, which is unsurprising. I imagine that it wouldn't be too difficult to find with a little Googling, but here's the thing, I think I'm going to recommend against doing that. Not just because you'll be in sketchy legal territory, but also because the update process didn't go very smoothly - my Blackjack froze on the screen you see pictured here. I was worried I was going to have a thin little brick. Luckily, though, it came out ok after I removed the battery. There's not a lot of surprises here - it's Windows Mobile 6 on a Blackjack. I don't think it's the final update, though, as the boot time was very long and there were a few little strange spots in the settings (Hardware Rev0.0 -- what!?).
So the verdict is: wait. I hope you won't have to wait long. In the meantime, you can stew by watching this quick little video of a Blackjack running Windows Mobile 6.