If I've not already said before, then welcome aboard
Things like Gamebooster (I think that's what it's called) already do this(ish), ending any unnecessary processes, and there are programs too to free RAM.
If I'm staying in the game and have no intention of alt-tabbing out to do something else I'll also pull my wifi connection so that's not draining resources.
Although I've had very few CTD's since using Win7.
Nice idea though, it'll help some I'm sure.