I agree MLeeK...that is why I asked ,"Can it deliver???" Sigma, and Tamron as well, are both pricing themselves higher and higher and higher...and I think in some categories, pricing themselves RIGHT OUT OF THE MARKET!!!!
Also, Sigma has started selling much,much closer to suggested retail than they used to! MSRP and MAP (Minimum Advertised Price, a different thing) are now MUCH more in-line with one another. MAP is the lowerst price that a dealer is allowed to advertise a product for and still receive cooperative advertising dollars from the manufacturer...so...if say Niukon says the Minimum Advertised Price on a particular lens is $1,099, and the MSRP is $1,249, then dealers can NOT advertise the lens for LESS THAN $1,099...or they lose the co-op advertising money from Nikon....which is worth a TON of sales!!!
I dunno...the way the resale value on 3rd party lenses goes down so far,so fast...and with Nikon just announcing a new 70-200 f/4 "affordable" pro-grade travel zoom at basically the same price point....and Nikon VR-1 and Canon's TWO "old" f/2.8 models, the IS and the non-IS, and Canon's TWO f/4 models, yeesh...I think Tamron is wayyyyyy late to the party with a $1499 product...why drop $1499 on a Tamron that's be worth $900 in 18 months--when an already-depreciated Nikon VR 1 or a Canon 70-200 Mark I IS USM can be had for the same price--and both will HOLD THEIR VALUE for a long,long time???
BUT, and this is a biggie--it *is* possible that Tamron can hit another home-run, like they did qwith the 28-75 f/2.8, or even make a BETTER lens than that, and one that is REALLY, truly excellent, and worth the cash...and if so, that could be bad news for Nikon and Canon's sales on their "new" mark II models!