That is interesting, Sony had anounced its intention to join the CMOS research and production and true enough this new sensor marks another developmental mmilestone.  Canon, the first camera manufacture who started the CMOS trend, followed by Nikon and now seems that Sony with its financial muscle and know how is joining and may even lead this race.

Will the sensor price drop to the level that squeeze 3/4 systems out of the market?  My gues is that it will take a few more years.

I agree that MP is not everything - tests have shown that it is hard to differnetiate a 8 MP from a 12 MP test shots.  Well, having said that, it is also true that newer sensors have new features built into the design - smaller "gaps" between photo repository so that there are less pphotons "loss", larger micro lenses to collect more photos etc.  These (seosnor size, better design) coupled with better processor(s) would mean that for professional requirements (e.g. prints of A2 size or larger) - these devices would present better results.  Like all things - at the upper end, a slight improvement requires a large increase in cost.  

Unless the full frame sensor with advanced design features drop significantly in price I am not unduly worried.  I am still happy with my Canon 40D - not full framed.