I think it could still be implemented in a better fashion. When games are called off in real life it doesnt just effect 1 or 2 games it effects the whole country, especially in the lower leagues. However, on FM2011 so far I have had a few games called off due to snow but my game was the only game in the league to postponed.
I've seen quite a few news items of AI matches being postponed in the lower leagues on fm2012... a nice touch of realism by the way!
I just wish that the postponed matches were permanently listed amongst the fixtures and results with P-P instead of disappearing from the list. They are listed for so long but soon disappear. Infact I'm not sure, but perhaps this is a bug?
It's not a major problem, but in my game some teams in the lower leagues have played alot less games than other teams and I would like to view how many postponed matches they'd had on their fixture/results screen as well as being able to see the weather forecast for that day.