It's clear that Microsoft will bring something to Mobile World Congress. This is inevitable, and necessary. But yesterday's report that it'll be Windows Mobile 6.6 has been met with another saying it'll be Windows Mobile 7. So which is it?

The conservative choice would seem to be Windows Mobile 6.6, especially given the nagging reports that Windows Mobile 7, which we basically know to exist in some form, has been delayed—in release, if not unveiling—until late this year. But here's the thing: until yesterday, nobody had even heard of Windows Mobile 6.6. We've only just been introduced to the final version of Windows Mobile 6.5.3, which appears to be the ultimate expression of the wrongheaded 6.5.x ethos, and any interim releases, even assuming a late 2010 release for WinMo 7, would have a hard time finding handset support.

Now that Bloomberg is chiming in to say that WinMo 7 will be unveiled at Mobile World Congress, I think it's fair to bet on seeing for the first time in February. As for 6.6? I'm not convinced that it even exists, or that Microsoft is oblivious enough to press forward toward such an obvious, self-imposed dead end.

On another note, this has been some uncharacteristically tight leak control from Microsoft—we know practically nothing about Windows Mobile 7 right now, which is as refreshing as it is frustrating. [Bloomberg via Silicon Alley Insider]