I'm planning to upgrade my computer and torn between maxing out the system I have or investing in the X58 architecture.

I'm currently using a E6600 Core 2 Duo with 4GB of RAM (800mhz) on an Asus PK5-E motherboard which I built two years ago. My original plan was that one day I'd upgrade machine to 8GB (1066mhz, the max the PK5-E allows) and to the Core 2 QuadQ9550 to give the machine a good four years of life.

However, that was before the i7 came out. I use my computer mainly for software development , which I do inside Virtual Machines, and the i7 seems ideal for that because it no longer is limited by the speed of the FSB? And when I looked into it, getting 8GB DDR3 RAM isn't much more expensive than the 8GB of DDR2 and the i7 920 is comparable in price to the Q9550, which doesn't make much sense to me?

So the question is it worth swapping the motherboard out for around $250 and upgrading all three components or using that money on SSD or 10rpm drive for the existing system's OS/Apps/Virtual Machine drive? Or just put the $250 towards a completely new machine in a year or two? Would the i7 really give that much of boost compared to the Q9550 for what I'd be using it for?

Thanks in advance for your input!!!