New Lenses or New Computer?

in your situation, id say the lens for sure.

For one thing see what they do on Vista changes or revisions.
There will be some.
Additionally the price on what you want will come way down.
Use the delayed acquisition theory on computers(6 months minumum to 1 year))prices drop substantially.
They'll always be something new anyway very swiftly in computers.
Saving money and spending perhaps when deals on especially a portion if you have enough extra for a hobby saved always leaves you free to take advantage of deals as they come along....and if you don't spend it you always have it anyway
But its your money.

I was in the same situation as you about a month ago. This is what I did:

Well, the situation all started when my laptop broke. It just stopped working. I tried to figure out how much it would cost to fix it and needless to say I was betetr off getting a new computer. At the same time, mind you this is before my laptop breaks, I was looking into purchasing the 70mm-20mm f/2.8 IS L. I was already about to make the trasaction right before my laptop took a fall.

So I had to choose:

Lens.
Computer.

I had to think about it for a couple days, but then I figured out what I wanted to do. Which is actually what I ended up doing. I went ahead and bought all the components I needed to in order to build my own computer. Everything I wanted. It cost me close to $1,800 which is about the same price as the 70mm-200mm. While making the decision I also considered school. I have two online courses and my school is about 20-30minutes away from where I live. So I don't want to keep using the computers at school and wasting gas. Also, programs that they use at my school are not MAC friendly. As much as I wanted a MAC for editing and processing, I couldn't do it.

I guess what I'm trying to say is that you need to get what is more important to you first rather than getting what you WANT. Get what you NEED first.

I hope that wasn't that long, but I hope it helps.

The new intel based Macs can run Windows natively via Boot Camp...

Which means a Mac can run Windows just like a PC can, which means all your games will work on your new Mac.

Just a thought if gaming is the only reason holding you back from getting a Mac. You won't find a better machine to do post processing in my opinion. Macs are built for this type of work.

Good luck with whatever you choose.

and chicks dig Mac users...lol..i keeed

Looking at what you have I'd think you could really use the lens.

Well I think I'll be going with the lense guys

About the Mac thing, I don't think I'll ever go Mac. The loss hardware options and gaming would be too inconvenient. If I'm correct, Macs need special hardware, like you can't just slap any video card into their systems....but I may be incorrect.

I use a G5 every day for photoshop, I hate the single mouse set up. Yeah I know most of the common shortcuts but I really need the right mouse button and the mouse scroll!

it's not like all of us are editing 10000x10000+ resolution photos anyways. My 1D mark ii only does like 4000x3000 anyways. to use a mac just for "graphics" is kind of silly