You know why they call it Thunderbolt instead of Light Peak right?.. Thunderbolt use copper. =\..
Sandy Bridge is almost out of date. Ivy Bridge is coming out 2nd half this year. If I remember right 10-20% faster. And 4,6, and 8 core.
Out of date, pff! Ivy Bridge is just a processor shrink. The real solid is the architecture that came out with Sandy Bridge. Going from non-SB to SB is the real boost - another 10% due to manufacturing awesomeness is just icing =)
The copper is a good thing, imo. It let Apple daisy chain off of existing ports instead of having to provide both a Light Peak interface and another DVI/USB/etc interface.
-j