I am using 2011 SP 3.0 and it still exists.
If you RC on the annotations in the feature manager
and show feature dimensions do they show up then?
Thanks for the replies - displaying annotations in feature manager works, but seems to display all dimensions all of the time (which gets a bit crowded!). Instant3D seems to be what I was after - everything displays as it did in 2010 now! Thanks for your help.