Good question, Paul!

I had the correct answer,but only thanks to the fact that I attended SQL Saturday in Portland a few weeks back (just before the PASS Summit). I don't recall who said it, probably either Buck or Rob, but the quote itself will always stick: "Exection plans suck". Refering to the little-known fact that data is not pushed from right to left (as most people usually read plans, myself included), but pulled ("sucked") by the top-left operator from the operator to the right and below it.