Things are still silly in the digicam field with shirt pocket cameras now up to about 12MP. This means 2.8 micron pixels (or maybe even less) which if this trend continues will begin to impinge on the size of the upper wave lengths of light. Stuffing photons into these little holes is going to start challenging the laws of physics pretty soon.
In the DSLR world sanity seems to be settling in, with pixel counts in the 12 – 14 MP range becoming the norm. The high end of the pro DSLR market seems to be at the 21 – 24 MP range, and while that leaves room for the lower end of the market to still move upward, the ceiling isn’t going to get much higher once pixel count gets above 25MP and photosite sizes below 5 microns, because noise will become too big an issue at anything other than moderate level ISOs. Photographers now want image quality above pixel count, or at least I do.
Check it out here.