It has been like it for 5 or 6 months now from memory. Basically there are structural issues with the floor, so it has been ripped up and work is going on to assess the problems and then correct it.
I work around the corner from Deansgate and I've noticed that there is normally some work going on during the day time (10-4pm or so) but nothing much happening around that. It doesn't look like there has been much material progress in that time from a layman's point of view, but obviously I'm no expert in such matters.