so no Bulldozer is worth buying right now.
I wouldn't say that necessarily. What Benchmarking sites (including this one) DON'T tell you, is that for gaming they're deliberately benching games that are known to be more CPU intensive. Which makes sense to some degree, the point is to test the CPU and see how well it performs. But again, most games on the market are limited by the video card as I said.
This is what you're typically going to see as far as performance in your typical computer game, there are a few exceptions of course like Skyrim and Starcraft II, but even those games the FX is
good enough even if it isn't the best:
http://www.overclock.net/t/1210060/fx8120-vs-2500k-benchmark-results
Honestly, if you can play a game at or over 40FPS average, only the most anal videophiles are going to have a reason to complain about quality.
How significant of an upgrade is an AMD X2 6000+ to a Phenom II X4 945? Gaming we talking about here. I can use the Phenom on my AM2 board.
What board brand and model are we talking about here? Have you checked the CPU support list on the website to make sure it indeed does work? Really I'd need more information about your system, the whole specs, what games you're playing to give you a reasonable answer on whether or not its worthwhile.