I can confirm that Google Calendar sync has stopped syncing via MfE about 1 or 2 days ago (don't remember when exactly) - before then it was working OK.

I have created new local calendar on my N900, which synced with GC straight away, but subsequent sync didn't work. Looks like only full syncs are working, but not incrementals. :(

I reckon there is something wrong on Google's side and we can't do much about it...