Its definitely an interesting choice, I've only held back on recommending it wholesale for gamers because there's still a lot of dual core optimised games out there that have demands that are
possibly slightly above what you'd get out of a stock X4 620. The 2.9ghz speed of a 435 is the right side of where you want to be but 2.6ghz is kind of borderline for me, but getting 3ghz out of it even on the trash stock cooler should be easy as pie (if you could try that it'd be wonderful) and that's when things get interesting for me. Anand managed to hit 3.25ghz on stock volts and cooling, which is pretty nice.
If you can, I'd like to see how it holds up at stock in stuff like Crysis, Stalker and any other high end games that aren't particularly multithreaded that you can think of. If its good enough at stock that it won't bottleneck a 4870 class GPU at high settings then there's no reason not to go with it really, as most CPU heavy new releases are optimised for at least three threads these days and in them it'll spank any high end dual core for under $100, which is really nice.
Fwiw, if I was in the market for a low cost quad, and I very well may be soon, it would get some serious consideration from me as once that thing's clocked its going to eat up anything you throw at it. That its on a platform with a bright future is even better.
Oh, and since we've been discussing SSDs lately, I suggest everyone read this, as it looks like
Intel have finally been dethroned as SSD speed kings:
http://www.anandtech.com/storage/showdoc.aspx?i=3702
Edit: Here's a table of X4 620 OC's from
www.overclock.net users, seems 3.4-3.6ghz on low end air is very much an achievable target which really makes it a great little chip imo. Definitely a great low cost option for OCers (and really we should
all be OCers imo, if you can build a rig, you can OC a chip).
http://spreadsheets.google.com/pub?key=taqpnD0wwBf7ZIijViCtnFA&w=100&h=500