But that's the thing, if the SSDs are all you are waiting for, then might as well build now with regular HDDs and then upgrade to SSDs later. Or even you might be ready for a new build by the time SSDs become viable.
SSD's aren't the only thing I'm waiting for; I'm also waiting for the price to come down on DDR3 and Intel 7i processors, and I'm content to squeeze the remaining life from my current setup in order to extend my time between upgrades, since I can't afford frequent upgrades.