Well I think your PSU is waaaay overboard for your setup. What did you want rated, BTW??
** CPU is good, still, but starting to get a bit dated.
** Mobo should be good, but if it's whining than maybe it's time to replace?
** RAM seems good 4 x 2 gb's??
** GPU is a good one, runs hot I'm sure, but that is expected with a 4890
** Rest seems good.
The 4890 is a good card. It should last you for some time. When things start to seem a bit slow, you can 1) OC the CPU (assuming your temps are good) 2) build a new system and re-use some of the other parts (i.e. DVD drive, HD, Case, PSU, etc.)