So when Nikon released the updated version, I was a little hesitant to upgrade - at least until I went to audition the new lens in one of the big NYC camera shops. After using the new lens firsthand, I just couldn't resist. Now, I own the new one, and the older one is on eBay.
To me, where the compelling value comes from is the new AFS focusing setup, making autofocus nearly instant and incredibly accurate. Thanks to the wide f/1.4 aperture, you always get a bright image, and on both my D3 and D300, focus is blindingly fast and dead-on accurate. This was my only real gripe with the previous lens, and I found myself often either missing shots because of the slow autofocus, or I'd spend a lot of energy manually focusing instead of composing the exact shot I wanted. Now, with the new 85mm f/1.4G, I get fantastic image quality, plus much better and faster handling - and to me, that makes it worthwhile.
Still, the older lens is no slouch, and I suppose if I had neither one and was on a tight budget, I'd certainly have no trouble going with the older lens. There seems to be maybe a $500 premium to get the AFS version, although that might narrow as more lenses get into the market and we see some better discounting.
Nikon 85mm f/1.4G AF-S Nikkor Lens for Nikon Digital SLR
Of course, if you're questioning whether to upgrade, the pro-grade Nikon lenses hold their value very well, and although I haven't sold mine yet, I'm thinking I'll get 80% of what I paid for it when it was new several years ago, and that makes the transaction easier to handle.
Definitely recommended.