This is something I noticed yesterday, when my Windows Mobile phone (a T-Mobile Vario II running WinMob 6.0, since you ask) failed to recognise the British Summer Time shift.
Now today I see that some other users had the same experience (although some didn't, so it may be a version-of-WinMob thing). No biggie, obviously, but certainly odd. I seem to recall the daylight savings shifts happening quite automatically in the past - I wonder why this one was different.
Oh well. Some explanation from Microsoft will surely be forthcoming.