Well the release pace appears to have dropped off somewhat, http://en.wikipedia.org/wiki/List_of_Sony_A-mount_lenses , but I daren’t prophesize. We have since rather recently a 300g2, 70-400g2, 500f/4, 70-200g2 and acc. to that Wiki article improved 16-35 and 24-70ZAs upcoming.
Still, as great as the A99 and A772 and the 70-400 are, you go where the money are in the end and would you then choose the new tunnel that glitters or continue banging your head against the Canikon dslr mountain?
I have no doubt that they will continue banging their head for a number of years to come. Beyond that, hard to say, with the way the tech is evolving. (Which is “slowly” on the Canikon mountain, and that is attractive to a common mindset)
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.