Engadget Mobile points us to TXCaesar's Rom Kitchen, where Da_G has cobbled together a build of Windows Mobile 6.1 for the original BlackJack. We waited and waited (and waited some more) for Windows Mobile 6 to be officially available for the BlackJack, so it's a safe guess (if a depressing one) that we'll have to do the same for 6.1 on the BlackJack. That's assuming, of course, that it will be made available for the sweet little guy in the first place. He has a newer, cooler brother in the BlackJack II (which will see 6.1 for sure), so it doesn't feel like a safe bet that 6.1 will appear on the original.
The ROM looks to occupy the netherworld between