well there are still more procesors due to come out on this socket but amd ave already announced their next socket. id say it is still a very safe bet yet, you can have dual cores on them so you are safe for a good couple of years, and of course pci-e is the future so make sure you get that.
I think they'll be around for a while yet. Won't be phased out anytime soon, thats for sure. I would get PCI-E if you want to be future-proofed a bit more tho mate