I think Ivy Bridge is going to be the better bet. The main things LGA 2011 has over LGA 1155 are:
- 32 PCIe lanes vs 16 in LGA 1155
- More 6Gbps SATA ports
- Quad channel memory
Regarding #1: Ivy Bridge will get an upgrade to PCIe 3.0 and will have the same bandwidth in 16 lanes as LGA 2011 has in 32 lanes. So this is meaningless.
Regarding #2: Most high end LGA 1155 boards complement the standard two 6 Gbps SATA ports with 2 more. Unless you're looking to do more than 2 SSDs it's unlikely you'd need/use more than the 2 (or 4) 6 Gbps ports.
Regarding #3: It's pretty easy to get a dual channel kit that will run up to 2133MHz with LGA 1155 and that makes up for quite a bit of the memory bandwidth difference.
Pros for Ivy Bridge:
- Smaller manufacturing process so it'll be more energy efficient.
- And the normal optimizations will increase core performance over Sandy Bridge E.
I'd definitely go Ivy Bridge. Outside of needing to fully populate 8 dimm slots (max of 64GB) or running large RAID arrays with the 10 SATA ports I don't see Sandy Bridge E being a gamer's chip with Ivy Bridge hot on it's heels.