So far I'm pretty impressed with this lens. This is actually the first time I have ever used a third party lens. I've been going around inside shooting snapshots now that it is somewhat dark and even without the assist lamp, it has not missed a shot. The VC is definitely it's strongest feature, it's pretty solid all around with the exception of wide end distortion. The Tamron and Nikon both suffer from the same distortion issue and both have their own "sweet spot" optically. The build quality is very solid, the Nikon still wins there. If I were a pro Wedding Photographer, I would probably buy the Nikon, but the Tamron is definitely up to the task, ever so slightly behind the Nikon in the Bokeh area. As far as my interests in an event/people lens, this would fill my needs, but I'm not so sure I want to lug an almost 2 pound lens around (the nikon is 75 grams heavier).
In reading reviews of the Tamron, many pros that worship their Canon and Nikon pro 24-70 2.8's all spouted that the VC (or VR) is a waste and not needed in that focal range. I agreed with them until I used it, they (and myself) were completely wrong. After shooting the cat shots at 1/10s I became a believer fast. I'm not that much of a snob to not realize when someone has something better and (temporarily) has an edge. Once the Nikon comes out, it will of course be stellar.
Price wise, it is a difficult decision. If it were below 1K it would be in the bag. At this point I'm thinking my casual lens is going to be a Nikon P330.