Intel is going to be splitting the market into three sockets (and this three sockets are not going to count the server sockets.) Almost all the info I have seen has been about the

For more info look here
http://pc.watch.impress.co.jp/video/pcw/docs/360/112/6.pdf

Note I am going to be explaining the pci express lanes in the way that is most configurable for gamers.

LGA2011
1 or 2 physical cpus
Each CPU can have 4, 6, or 8 cores
TDP of chips can be <80w, 80w, 95w, 130w, 150w
40 pci express 3.0 lanes so 16+16+8 / 16+8+8+8 / (and various smaller configurations)
4 (Quad) Memory channels with (official) memory up to ddr3 1600mhz or 51.2 GB/sec maximum memory bandwidth
Patsburg PCH (aka the southbridge or what determines the speed of your sata ports, raid, etc)

LGA1356
1 physical cpu
Each CPU can have 4, 6, or 8 cores
TDP of chips can be <80w, 80w, or 95w
24 pci express 3.0 lanes so 16+8 / 8+8+8 / 8+8+4+4 / (and various smaller configurations)
3 (Tri) Memory channels with (official) memory up to ddr3 1600mhz or 38.4 GB/sec maximum memory bandwidth
Patsburg PCH (aka the southbridge or what determines the speed of your sata ports, raid, etc)

LGA1155
1 physical cpu
Each CPU can have 2 or 4 cores
TDP of chips can be <65w, 65w or 95w
20 pci express 3.0 lanes so 16+4 / 8+8+4 / 8+8+1+1+1+1
2 (Dual) Memory channels with (official) memory up to ddr3 1333mhz or 21.3 GB/sec maximum memory bandwidth
Cougar Point PCH (aka the southbridge or what determines the speed of your sata ports, raid, etc)

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I have personally seen very little about the mid socket the LGA1356; extrmely little info on 1356. I have seen a lot of info on 1155 and 2011 sockets.

In some ways 1356 is a sidegrade of the current 1366 (which the x58 uses). The current x58 chipset has 40 pci express lanes instead of 24 pci express lanes but they are the slower pci express 2.0 instead of 3.0. Now sandybridge is focusing on bring the tdp of processors lower since most people don't need the best of the best and lower power consumption and less heat is good. That said the current 9xx series of processors are 130w tdp, the 95w sandybridge cpus may outperform the current 130w nehalems but in theory the 130w and 150w sandybridge should perform even better. Finally while socket 1356 will have 50% more bandwidth officially than socket 1366 you are also doubling the core count so each core will get less bandwidth. 2011 socket will have the same bandiwidth per core as current socket 1366. So in sum the socket LGA2011 is better than the LGA1366 in everything while LGA1356 is a sidegrade in some aspects.

LGA1155 is a sidegrade of LGA1155. It is still plenty fast but it won't be used via anything better than a quad core.