Yeah ticks have been always been 12 months - if we consider Clovertown to Penryn and Nehalem to Westmere - but with the tock cycle getting longer and Intel's dominance I certainly won't be expecting Ivy Bridge EP within 12 months. 15-20 months before an update wouldn't be surprising in the least to me.
I'm missing the logic behind the tock cycle getting longer having impact outside of the tock cycle. If Haswell needs to ship later then it can just slide out. Sleeping on Ivy Bridge isn't going to shorten that cycle. The only thing that would 'slide out' Ivy Bridge is if they pulled some Haswell features forward and make the Ivy Bridge a hodge-podge tick+tock cycle. That's a dubious move.
It would surprise me (12 to 14 seems more likely). One of the primary reasons Intel has AMD so off balance is that 12 month regularity. If Intel throws that out and goes to extended development on both parts of the cycle, they are basically letting AMD get back into the game on AMD terms. I extremely doubt Intel is going to do that.
Right now what keeps happening is every couple of cycles AMD tries to 'swing for the fences" and hit a home run ball (usually a combined shrink+arch cycle). In part because there isn't enough time to 'catch' up.
I suspect Intel is going to have to let real, working engineering samples do the talking to the NDA partners at this point before putting voodoo dates down on paper. Ironically, Intel has joined AMD in the "yeah right, you are really going to hit those dates" club. That is not really a club they would want a long term membership in. Getting out is easy. Just stop rushing to write down dates before have enough info to write down a creditable date. If Intel posts a Q1 2013 roadmap date for Ivy Bridge EP in June the world won't end.
Your last sentence basically sums it all up sadly - Intel wouldn't have waited 2 years if Bulldozer Opterons were a good alternative.
Bulldozer would have been a much more creditable alternative if AMD had hit the targeted clock rate and got the OS scheduler updates out on launch. Intel pissing around for an extra 6 months would give them most of the time they need to get that corrected. The OS scheduler updates are already out and if give AMD 12 months to shrink and clock bump they probably will.