I am very sorry, I must have skipped the part with your iMac due to me reading MR in the morning. In that case I can see how my post didn't make sense at all.
If you have an iMac 20" (Intel I gather)now and don't feel it's enough for the task, I doubt an iMac will fill its shoes. Seeing as the only real difference is the graphics card and a bigger screen, it might not be snappier at all. Unfortunately a Mac Pro is probably more than enough for you right now (unfortunate because it's a lot of $$) but at least it will be able to handle what you throw at it.
Where 64-bit/multicore apps are going from here, only time can tell but if the development is just as slow as it has been for the past two years, it will iMO probably take two more years before it's the norm and you can do anything really useful with it... For now the OSs will be the ones taking care of the multicores and 64-bit.
Hope I was a little more clear this time...
Much. And I'm still hungover and understood it this time. So you've really stepped up your game.
The other diff between my current 20" iMac (first gen intel) and an iMac 24 is the processor. My current machine is a Core Duo, 2GHz, 2MB L2-- the 24" has the Core 2 Duo, 2.33GHz, 4MB L2.
I've gotta do some research in how great the performance gain is from Core Duo to Core 2 Duo-- I've been told it's considerable.
Happy Thanksgiving gang!