Well, megapixels aren't everything. Keep in mind Nikon/Sony's 24 megapixel sensors are full frame (vs APS on all other ones you mentioned). The 50D still has a greater pixel density at 15 on an APS. They do some impressive things with noise performance on the 50D, utilizing that pixel pitch very well, other then that, performance differences between it and 10-14 Megapixel APS sensors is minuscule. On its own, 10 megapixels is plenty to work with, also consider - the higher the megapixel, the slower the work flow on your pc, and 12 Megapixels even take quite a bit. Processing one of those 24 megapixel Raw files and pulling it through a multi-layered 16 bit workflow will *require* quad core cpu and copious amounts of memory (vary by OS). That is one thing I miss about my 6 MPix DSLR – very very fast and easy workflow, even the 16-bit layered raws.

I can't just suggest one camera though - all manufacturers make great options, and each has their own nook in the market where they perform particularly well. If you tell us more about what kind of shooting you do, we could give you a better suggestion on a DSLR system.

'This side of Zeiss' - you know there is a DSLR manufacturer that actually uses newly designed, autofocus Zeiss glass?