The conclusion is that as your system budget goes up, SSDs are more and more attractive. Which is largely obvious, but it recommends them starting at around $1k, which seems a little low to me.
TLDR: If your budget is high enough, look at the Crucial C300 RealSSD (overall performance), Intel X25-M (cost/value), Corsair Nova (overall value). Consider the Agility 2 as well, but the cost is a little higher than performance may warrant (though it's the value leader for the Sandforce drives and owns some of the benches).
I think the $1K recommendation is assuming the computer is general use and not specialized. A build that isn't specialized for gaming wouldn't need to spend more than $150 on the GPU (the 5770) or over $160 on the CPU (X4 955). Assuming those parts, and basic prices on everything else, leaves you with about $300 after the full build. That would be enough to consider a SSD.
For gaming PCs I find SSDs a waste of money. When you've got 3 screens, good gaming peripherals and enough horsepower to run every game on highest settings then an SSD would be a good idea, but spending 350 for 120gb storage which can maybe hold your OS and 5 large games or apps when you could spend that on 2 extra screens for surround seems ridiculous to me.
@somebody: Those are crazy large games/apps (16 GB each), but I agree mostly. I think that after you have the i7-930, the 5970, some super fast sticks of RAM, and a highly efficient PSU, the next step is the SSD. After that, all the extra monitors and such would come into play.
Definitely once the prices come down to where you can get a 120 GB SSD for $150-200 there would be no reason not to include a SSD any more.