Well, I think your scenario for application development seems unconventional, or at least outside the realm of most development scenarios. But then again, I come from the Java Enterprise world. And you could still go buy a dual slot, quad core handling setup from newegg, throw Ubuntu on it (or OSX86) and have it be cheaper. But I realize that most people have no desire to go down this route.
Virtualization is pretty common, and getting more so every day. People are starting to look at their space lease and electric bills.
And you could still go buy a dual slot, quad core handling setup from newegg, throw Ubuntu on it (or OSX86) and have it be cheaper.
The retail cost of the equipment in a Mac Pro tends to be more than the cost of a whole Mac Pro. Apple must get some good volume deals. The Mac's 1600 MHz chips aren't on the retail market yet, but the slower 1333 version of the 2.8 would cost me about $1,500 for two. Looking at the price difference on the last bus bump, add maybe $300 to that. Now I get a mobo ($500) and power supply ($300) and I'm within $200 of the Mac Pro's price. Hope I can find the case (quality aluminum, quiet please), heat sinks/fans (gonna need good ones), video, memory (FB-DIMM), keyboard/mouse (must be decent) and hard drive really cheap.