Been using the Sensation since release and have no screen issues; UK Vodafone - no case.
I feel for those that have the problem but be careful jumping to conclusions and blaming HTC alone - don't forget that carriers introduce their own updates.
Slightly off topic: I've been running GoLauncherEX for over a week now and it's so much faster than HTC's Sense 3.0. It also offers more efficient screen use (more widgets) and has a whole bunch of customisation options. Sense for me could be a thing of the past...