Ouch, usually I'm all in favor for more competition from 3rd party gear, but for a $1000 lens Tamron should have done better than that. Canon will be happy, more people willing to pay no matter what for the 24-70 mk2 as this will be the only alternative in production...
Check out the mark 1 24-70mm that has been dropped a few times (onto concrete) by DigitalRev staff, and they're still using it.... they're absolutely bullet-proof
6 years.... and it is better than the 24-70 I, has IS and is cheaper.... depending on how often this happens, i don't think it has put me off too much... not that i'm in the market to buy one any time soon!