If AV or some form of it were to pass in 2011 would that mean that the Liberal Democrats then back the constituency-resizing and reduction in the number of MPs program? IIRC they backed out by stating that it and the AV issue were linked so since they didn't get what they wanted they wouldn't support the other. Have there been any studies on what the combination of the two might of meant for future general elections?
Not quite accurate. They were willing to go along with redrawing the boundaries to try and equalise the size of constituencies while reducing the number of MPs until it became clear that there were enough Tories opposed to changing the House of Lords to scupper the reform of the second chamber. It was at that point that the LibDems pulled the plug on boundary reform, not when AV failed. At least, that was the case in public, and I doubt that it was any different in private. What surprised me a bit about that was that when the LibDems went through on their promise to not vote for boundary changes in the absence of a reformed Lords there were plenty of surprised Tories, despite the LibDems having made this position clear before Lords reform was shelved. I suppose they either felt the LibDems were poodles who would do whatever the Conservatives want or they believed the LibDems wouldn't keep any of their promises.
Having said that, I suspect that the LibDems would have gone through with the boundary changes if AV had succeeded, whether or not the Lords was reformed. How AV and boundary changes would effect the 2015 election is anybody's guess.