If you already have the I7950 I would hold off upgrading to the I7980X for now unless you really don't mind overpaying for that processor. Once Intel releases the next wave of cpus the price of that chip will go down, It may be a year or so before you really see the price drop where it needs to be but I think you will save 100's of dollars playing the waiting game.
Your cpu will do fine even with the crossfire if you OC that cpu to its potential. Try OC'ing 1st and go from there.
You have a sweet system as it is. I used to have to get the latest of the greatest. I have an 8800GTX ACS3 video card that I paid 600 bucks for over 3 years ago and now its about 1/4 to 1/3 the performance capacity of the same priced cards today.
You will find settling on the sweet spot of price/performance on hardware is a much better investment and still quite a fun hobby. The money you will save can be used to get a nice set of tires for your truck or a new water heater when it goes out, lol.
I'm glad you were able to get your hard drive installed. =D