On the contrary, considering the late start in comparison with Canon, Nikon, Pentax, and others Sony managed to steal marketshare from all of them and get to third place worldwide in DSLRs and that may not include the Nex or SLT series sales.
What you don't seem to understand Derrel is the big picture.

Most of the pros here on this forum work in limited fields with limited scope. Beyond this forum there is a super broad range of pros who use everything from medium and large format digital cameras and backs through to those that are using DSLRs and even point and shoots or pocket cameras and many who use all of the above. I have used Sony, Minolta, Nikon, Canon, Pentax, Panasonic, Leica, and others and by the way I do not own an A77, so you jumped to another wrong conclusion. I don't need to justify any purchase but I can put unique new features to good use in my work and that is important.
The flipping mirror is dead. It is reaching its technological limitations. It is time for a new approach to go beyond those limitations of speed and vibration problems. Each Sony implimentation of the SLT has got better and the A99 will be better than the A77. Nikon and Canon may play a wait and see approach to the marketplace reaction to the Sony SLT but you can bet your bottom dollar that they will copy or adapt the concept if they think that the public will buy it. Either way, Sony has started the move to drop the flipping mirror and that is how changes in technology take place.
skieur