It appears O2 UK have beaten their target window of Mid-April for the Galaxy S II's update to Ice Cream Sandwich by a long shot. It's still March – late March, mind you, but it's March – and the update is now rolling out to users. You'll need to get it through Kies, but we're sure that small inconvenience won't bother most of you.
Android Phone, O2 UK Galaxy S II Now Receiving Android 4.0