Intel likes to have a new socket for every new CPU.
As I have said before, and I'm sure others must have too, sockets are pretty much meaningless.
You can have the same socket for 10 years, but that doesn't mean a CPU bought at the end of that 10 years will work in a motherboard bought at the start.
Chipsets and sockets go hand in hand. It's better to change socket regularly if you're not going to have support anyway because the chipset isn't capable.
It makes it much easier to know whether things might work or not. Most socket 1155 boards, with a BIOS update, will support Ivybridge.
If they kept socket 1155 for the next gen mainstream processor, that doesn't mean it would work in ANY existing motherboard, because it will probably require a new chipset.
Changing sockets makes things easier for US.
As for the OP, at best it would be a minor speed boost, perhaps some better overclocking, but no real overhaul that will make any sigificant differences.