The biggest drawback to multiproc systems, other than price, is overclocking. You can't achieve much, if at all in some cases.
Games will run great on a 250, just understand that you will in the vast majority of cases, not realize a benefit from having the second processor, other than reduced multi-tasking hiccups.
If, by chance, you are considering running Linux on this system, forget ATI completely. As much as I like their hardware, and I do, they simply don't seem to give a rats ass about decent Linux drivers. Nvidia, OTOH, has proven consistantly to care about Linux, and is the only real choice for a system that someone wants to run Linux on with good performance.
I have a dual Opteron 248 myself, absolutely love it. Only have Linux on it. I have 4gb of RAM, but honestly, 2gb would probably be sufficient for me the majority of the time. I rarely use more than that. Although when I do, I'm glad I have it. Good luck.
<i>Nemo me impune lacesset</i>