While I can see the varying opinions here, take a look at what Microsoft is facing. As a product, Windows Mobile is shifting further from the PDA market and rapidly towards a cell phone market. They are now facing a media rich competitor with the iPhone, and with the googlized phone coming, more competition. So I don't see it so farfetched that Microsoft (with the blessing of HTC) might step in and offer to finish where HTC left off to build a base of better PocketPC phones with great graphics. Then they can start to compete on numbers. Remember that for many people, word of mouth on the phone is powerful (no pun intended). The more people out there with phones that are playing movies, youtube, etc (hulu?) will mean being able to pull some of the steam from the Apple train. If you believe the mobile device will gain in popularity over time, then you can understand why Microsoft might step in to "help" get deveices up to par. I see the Mogul and Touch as being sort of transition devices. They learned a lot from them as finally the hardware and software crossed a cusp where they became uber useful.
So, should HTC have been the pne to handle the updated drivers? Sure. Does it *surprise* me that Microsoft might do it themselves (with cooperation from HTC I'm sure), not at all given the current market. Do I believe they actually are doing it? No idea, but I hope so
And or the posters that assume all the masses will upgrade at the release of the Diamond and Touch Pro, I'd have to say "I doubt it" due to the cost, I know I won't (until my Mogul breaks and insurance helps the upgrade). And besides, then there will be a flod of used Touches and Moguls on the market that are still useful.