A Windows Mobile 6.1 update for the HTC TYTN II / Kaiser will be officially available any day now (likely by the end of the week). So says Paul of MoDaCo, adding:

The update is for HTC TyTN II devices, and will be followed later by a AT&T branded update. The update adds Windows Mobile 6.1 with improvements such as the 'Getting Started' wizard, Threaded SMS and general performance and battery life updates, as well as HTC's 'video performance' update. So what's it like? Performance IS improved, however with no real video acceleration, don't get your hopes up TOO much!

...So it looks like our fears last week that the update would never be seen on the Tilt were unfounded. We're happy to hear that the update is 'improved' and though we understand (and partially agree with) the decision not to try to develop better video drivers, the lack of them here still stings, just a little.

(Oh, right: following that MoDaCo link will start you on a path towards hunting the leaked version of said ROM, which is indeed out on the internets as of this moment.)

Thanks to surur for the tip!