All specs aside, I really think that this is a knee-jerk reaction to the market / sales.
With the Tamron getting to market first, many fans held out. But as delays came on folk began to jump ship - especially when the price was verified by the vendors.
With the v1 24-70 gone, all of the sudden sales are down, even with a proported fatter margin on the v2.
We've all read the rumors that there was an IS version being tested - but this all went out the window once the v2 was Announced.
Many consumers will prefer to stay away from off brand even at f4 vs f2.8. I would expect simpler housing, pricing iine with Tamron VC 2.8 24-70.
Kit option - possibly.
Another marketing gimmick - "you don't need 2.8 anymore - just push your ISO - it will still look great - oh, you don't like the 3200 on 7D or rebel ? Well there are the new low noise high ISO bodies just for that. Buy the new body, save on the lens."
Ok - so I'm taking the conspiracy apple box stand.
We a bit jaded as far as lens prices go - and should try to step back and see this from a mass market POV. That is, after all, where this lens is targeted.
If and when there is something to consider - we will. Just take a look at the harsh 6D reactions from the announcement, and now people slowly peeping in "I'm considering it"