On the last question about whether or not there should have been another raid to help hold us over, I think the issue isn't so much the amount of content but the spacing of it. Specifically that DS came out WAAAYY too soon. I mean they knew ahead of time that there was only going to be 3 raiding tiers this expansion (I'm not sure but I think I remember it being said that 3 tiers per xpac was the intended norm and that Wrath was an exception and that ToC only happened because they weren't ready to put ICC out yet).
So if you look at a 2 year expansion cycle, or even knocking a few months off of that for an "accelerated release schedule" and you should still be looking at 6 to 8 months within each tier, but let's look at the patch dates:
4.0 came out in 12/10
4.2 came out in 6/11, that's 6 months that we spent in T11, which is a good figure if aiming for the 1.5 year expansion, but a little early if it's going to be closer to 2 years.
4.3 came out in 11/11, that's only 5 months that we had of T12, they're clearly jumping the gun as this is less than what we should have for a 1.5 year cycle.
And for the next comparison, even if we get MoP in September (which seems the earliest we'll probably get it) that would be 9/12, which means 10 months of T13. That's twice as long as we had Firelands for, nearly as long as T11 and T12 combined!
If 4.2 had been pushed back maybe another month to 7/11, and Firelands extended another 2 months too so that DS didn't come out until 2/12, then we'd currently have only been playing with DS for 5 months, and another 2 or 3 months wouldn't be nearly as bad (in truth it would probably be perfect since it would put us where we are now, but with MoP already coming out).
Now part of this may have been a result of them planning to have already released MoP by now so they released DS so soon because they didn't know that MoP would take this long, but my point is that if the tiers were spread out more evenly it wouldn't seem as bad as when we go from a 5-month tier into a 10-month tier. If you're going to have 3 tiers in an expansion then each tier should take up a third of the expansion's life cycle. 8 months per tier for a 2 year cycle (what we've gotten in the past), 7 months per tier for a 21 month cycle (what we're probably looking at this time), or 6 months per tier for a 1.5 year cycle.