This is another one where we just have to shake our heads and sigh.

CNET's Ina Fried posts on her blog [via] that Microsoft has told a handful of its partners not to expect a final build of its Windows Mobile 7 operating system until the second half of 2009.

Not exactly the sort of WinMo news we hoped to bring you on the day the first Android device is officially released.

Fried does write that we shouldn't have to go cold turkey as we wait for WM7, with an update to Internet Explorer Mobile still in the works. (Yeah, that doesn't make us feel much better, either.)

We are, however, reminded by Fried of a speech Microsoft CEO Steve Ballmer gave in April in which he spoke of the sweeping changes planned for WM7.

"The work we're doing on Windows Mobile 7, which is the next major release of Windows Mobile, not just in the Windows Mobile team, but across Windows Mobile, in Silverlight, the development platform, the e-mail, the back end, I think you'll continue to see that as an area of major excitement and innovation for the company as we move forward."

And while Silverlight has had a bumpy start, the rumor of a Microsoft-led application store could well be what's holding this whole thing up, and it could well be worth it.

In the meantime, Microsoft appears content to let outside manufacturers do the UI legwork, a la HTC's TouchFlo and the sliding panels on the upcoming Xperia X1, and third-party options such as SPB's Mobile Shell.

Group product manager Scott Rockfeld tells CNET's Fried:

"Customers don't have to sit back and wait. There's tons of stuff coming from us and our partners."

But we do have to sit back and wait from Microsoft. Again.