While I do agree that the FX4100 could be a waste down the road, I don't agree that a 8120 is a better buy than the 1090T at all.
I'll give you that, down the road, the 965
could be put in third place easily, right now is not far behind (in games) to justify the extra price for the 1090T or the 8120.
http://www.anandtech.com/show/4955/the-bulldozer-review-amd-fx8150-tested/8
If you look at the CPU testing for the games, the 965 (represented by the 980) still has a lot to give and hardly become obsolete in the near future. And since I cannot guarantee that "new" games will use more than 4 cores actively, the 1090T and 8120 are hard to recommend right now IMO.
Cheers!