I see what you guys are saying, but the change will happen, and to drop a good amount of money on a card that will physically outlive its designated slot is a hard pill to swallow. If this release was a couple of years ago, I would have no objections.
My point is that PCI-Express has been around since the 939 pin AMD Athlons; what is the hold-up? I have a PCI-Express wireless network card, soundcard, graphics card, and JBOD controller. That just about covers the gamut of add on cards these days. Unless you have a really expensive legacy device that is necessary for your livelihood, there really is no excuse for the motherboard companies to be dragging their feet. Change happens, and the more unified the slots are on motherboards, the easier (not harder) it is for the consumer.
I have a feeling that once the DSPs and processors are native to PCI-Express protocol, the change will come quick. Now if every board would have nothing but physical 16x PCI-Express slots (with a good electrical lane assignment), there would be no issue with regards to card placement.