Since when did these mobos come out?

My friend just got a dell and I was suprised in the most that it has PCI express and uses a X300 pci-e card. Then I checked on newegg and it seems that there's a new chipset called the 915. Why the heck did I never hear of this, and is it any good? Does it only work with Prescotts?

As far as I am aware the 915 chipset is for LGA775 CPUs and motherboards. So yeah its basically just for Prescotts as I am not aware of any Northwood LGA775 CPUs.

And what are the LGA775s? Is it the new socket? It sure looks like it.
Is there any point in getting one of these? Are there any tests out on the net yet? I would assume so considering newegg has about 15 of these boards. :/
Interesting, AGP and PCI-E x16
http://www.newegg.com/app/ViewProductDesc.asp?description=13-135-157&depa=0