What is your target price range? Do you intend on really overclocking? Because if you are not, then you could get a less expensive micro motherboard (if you can get a regular ATX motherboard instead, you'd save but I do not know if already have a m ATX case). Because you said you want to cut down, I am under the assumption you only want to optimize the expenses and not allocate the savings into a superior item.
This is just my opinion, but I wouldn't use that PSU. You could get an OCZ for comparably the same price or a Corsair for a little more.
I would stick with CPU / GPU.
Can you re-use a hard drive? You are definitely overpaying there at the moment.
Cheaper motherboard? Possible saving but you will probably have to lose some features. But are they worth the extra cash?
Include 1333 mhz memory in your options. You may find a better deal. Without specifics it's difficult to tell.
For your motherboard you can go a little cheaper with :
ASRock Z68 Extreme3 Gen3 LGA 1155 Intel Z68
ASUS P8Z68-V LE LGA 1155 Intel Z68
BIOSTAR TZ68A+RCH LGA 1155 Intel Z68
Power supply you don't need 650w change with this :
OCZ ModXStream Pro 600W Modular High Performance Power Supply
You can change the CPU if you don't overclock with Intel Core i5-2400 Sandy Bridge 3.1GHz quad core and you save another 30$.
If you go with i5 2400 thwn you can change the power supply with one with 550w : XFX Core Edition PRO550W.
Just with this two you can save a few bucks i say 70-80$ is cheaper now.
Yeah, 2500k + 6950 is definitely a decent "futureproof" setup especially considering Eyefinity. Even if you don't intend on overclocking right now, you could get a good HSF later down the road & unlock that 2500k to 4.5GHz in a snap.
You could opt for a P67 board if you don't intend on using Lucid/SSD caching/etc... as most will also be compatible to Ivy Bridge with a simple BIOS upgrade. Just don't do like so many do; make sure your board can support SLI/CFX @ 8x/8x at a minimum... that extra 20-30$ will save you some anger if you ever see some cheap 6950s in say a year and you'd love to get a lot more life out of your rig.
Buying a new HD right now is horrible, prices have jumped nearly 2x what they were before the floods.
Max budget would help a wee bit
If you don't care about futureproofing a wee bit, then you could save a bundle with cheaper Z68/P67 options, a lower clocked non-K CPU and even a 6870 to some extent.