Jerry, since you're new, look around. There are a number of threads on mid-Market, many of which I've posted because I too am interested in the area. One is
http://forum.skyscraperpage.com/showthread.php?t=133567 . But there are also threads on Trinity Plaza and so on. And don't miss the Business Times article I posted on the San Francisco Mart retail project--that may benefit you and other Fox Plaza residents as much as anything going on in the neighborhood.
I don't see why there's much concern about "the low income aspect" of the 10th/Market building. As I understand it, the "affordable" component (and remember, in SF people with very middle class incomes can qualify for that) will be in the lower tower fronting Mission St. and the Market St. tower will be market rate condos. The dual structure of the building may be a problem for the people who buy into it, but not for the neighborhood.
By the way--since you live at Fox Plaza, the Business Times also hinted that Archstone could be thinking about adding a second tower (on the eastern end of the lot where the Post Office is, I assume). I hope you'll be sure to let us know of any rumblings about that you may hear.