The current Canon 7D is indeed a great photographer's tool, and I think Canon raised the bar significantly when it was released as the 'king of the APS-C' cameras. I really like my 7D - and use it for taking photos from a whole range of photographic genres, from wildlife to landscape to 'events' to macro and a bit of everything in between. There is not much that it can't do very well - though of course for a number of dedicated applications full frame has some advantages.
For sure I would like to take a 'sneak peek' into the future and know what changes will be incorporated into the 7D mk II, and when. If the 7D mk II will be released by April 2012, I do not believe there will be many significant changes with respect to: body layout, AF, Megapixel count, or FPS, though Canon may have decided to make minor tweaks on any of these aspects.
My speculation about possible changes for a Q2 2012 are:
- use of the DIGIC V processor (one for processing) while maintaining 1 processor for AF (maybe a DIGIC IV)
- a newer sensor with improved noise characteristics / higher dynamic range
- possibly higher ISO range, eg up to 51,200
- some changes to video (perhaps continual AF and higher resolution / frame rate combinations)
- a number of software changes (eg menus, in-camera processing of some image characteristics)
- perhaps more advanced live-view functionality
- some connectivity / peripheral upgrades (wireless / wired and flash control)
I see such a 7D mk II being a modest refinement of an already very 'fine' camera. Perhaps less of an improvement than the 5D Mk II was to the 5D. This is just my opinion, if they aim to release the 7D mk II April 2012, in time for the 2012 London Olympics, it will be the 'non-professionals' choice of a very good camera.
However if a 7D mk II will be released after the Olympics, (eg October 2012, or even in 2013) - I believe we might see more significant changes possibly in the FPS and AF departments. The 7D enjoys very good popularity, and Canon will currently be realising a lot of continuing profits for this as a key prosumer APS-C camera. I do not expect that Canon will change the 7D mk XX sensor size from a APS-C (I hope not... for my purposes I like it as it is, and I have a number of high quality APS-C dedicated lenses!) I certainly don't need a 'new' or better camera... but like I expect a lot of people on these forums, I'm curious about any future DSLRs.
That's my 2 cents worth.