I'd say Scratch that itch a little longer before upgrading cpu/MB.
On current system I'd only upgrade components that would cary over to new system ie GPU and as ethel suggested a SSD.
(1) New intel chipset Z68 coming out shortly, Alittle further out (maybe 9 Mon -> 1 yr, Ivybridge (hopefully Intel supported USB3/Sata III vs added on marvel support), and BD.
(2) On SSD. The biggest single Bottleneck on a system is the HDD. I've upgraded both my laptops and my desktop to SSDs - What a diff in overall performance (Not really a boost to gaming). Recommend you buy a SATA III SSD (not C300). Min size 80 gigs, recommend 100 -> 120 gig (if deep pockets go for the 200 gig catagory). You would have to either (A) use on SATA II (Would not get full performance, but close on random 4K read/writes) or (B) buy a pci-e card for SATA III. A major player for this card, Asus, I think have discontinued the U3S6 card in hopes of boosting people upgrading their MB - Shame on Them. Luckly I go one when they first came out for my P55-UD4P MB.