Trying hard to justify a new computer

Going over my receipts for the last year in preparation for doing my taxes I realized I haven't upgraded my computer in a couple of years.  My current machine is almost 4 years old, but since I first bought it I have upgraded the CPU and video card.  The CPU is a AMD 4400+ and can't really be upgraded again since AMD changed the chip socket since after I bought my motherboard.  My video card is a 7950 GX2 which I went a little overboard on when I bought it, I wanted one a couple models down but it was the only one actually purchasable when I was shopping.  

Looking at what is out now, nVidia has their new GTX 280 cards at the high end, but Tom's Hardware doesn't have it in their GPU comparison chart yet they are missing the prior 9000 series cards also.  My current card is still fast compared to the other cards on the chart.  It is also really hard to make direct comparisons as all the review sites always use the latest hardware when looking at video cards, even the resolutions tested are now going up, the old standard was 1024x768 but most monitors now support much higher resolutions, I currently run everything at 1920x1200 for example.  Making even manual comparisons between the 7950gx2 from the chart and the latest gtx 280 review impossible.  

Looking at Tom's CPU charts comparing my 4400+ to the E8500 Intel processors it looks like things are looking up.  Most of the benchmarks show the current generation of CPU's having double or more the performance of the 4400+, and the 4400+ they are using is a slightly better version then the one I have, or at least it has the new socket.   PC Mark CPU for example the 4400 rates 4531 and the E8500 gets 8103, almost double.  But for the Windows Experience Index the 4400 rates 5.2 and the E8500 5.9. On my actual machine I get 5.0 for the 4400+.  Processor and memory are my two lowest scores at 5.0.  

One irony is while I focus on video cards quite a bit while shopping for a new computer is that I don't really play games on my desktop anymore.  A little playing around with Age of Conan, and I will probably play Spore when it comes out in Sept. But it is really more of a work machine.  It might also be time to try ATI cards again I have had bad experiences with them in the past and have found nVidia to support their cards much better.  I don't know if things have changed since AMD bought them a couple of years ago. The Radeon HD 4870 compares quite well to the GTX 280 and is much cheaper, about the same prices as the GTX 260.

One thing I will do for sure with a new machine is run a 64bit install of Vista, my current machine has 3G of memory not all of it is usable as my video card takes up 1G of address space on it's own.  With 64bit Vista I will be able to have 4G or more of memory and have the machine use it all. Most of the time memory is not an issue but if I need to run a virtual machine to play around with stuff it is.  I have been using my server for VM's but it only has 2G of memory which limits my VM memory size a lot.  When playing around with Commerce Server 2008 it likes 1G on its own for example.  

Most of my research was done on I also like but their site is really slow and  

I will look at things in another three months or so and see if I can put together a machine I like for under $2000, pricing out everything I would like seems to be hitting between 2200-2600 right now.  Three months might give me another CPU or GPU generation to evaluation also.