Since this thread was active, Tamron has released a new 85mm f/1.8 IS which has had very positive reviews. A mid-priced lens, it is much cheaper than the various f/1.2 and f/1.4 models, but significantly better quality than the various other f/1.8 units. And it has IS (or whatever two random letters Tamron use to indicate image stabilisation). I was impressed enough by the combination of quality, price, moderate weight, and IS to buy one a few months back.

Is it as good as the reviews say? Dunno. Haven't really had an opportunity to use it yet. I seem to be stuck doing birds and landscapes lately, neither of which particularly cry out for an 85/1.8.