I have my doubts about Blue Dragon, Mass Effect and the others because they aren't reputable franchises, and no one can be certain for sure that they will indeed move hardware. High sales? Of course. Attached hardware? Doubtful. If you base your facts on established developers, and that they are AAA games, then the same can be said about the PS3, but again, doubtful.
I don't think the MGS franchise was in a position where a console relied on them to really boost sales. Again, just by looking at the fact that sales are higher in the U.S., MGS 4 will move hardware in the U.S. Don't know about Europe or Japan.
Once upon a time, FF was unknown in the US (pretty much previous to VII... yes, hardcore NES guys knew it but not the general public). The same applies to MGS for the PS1. While I doubt Trusty Bell or Mass Effect will move many units in the US, I think Blue Dragon and Lost Oddyssey in particular will move quite a few consoles. At one time or another, every franchise was unknown. And the pedigree behind BD and LO are huge. And you know that MS will advertise the crap out of them (LO in particular, I think).
On the PS1, MGS was one of three big franchises that moved consoles. The other two were FF and GT. All were released in a small amount of time. I hadn't played a PS before going to a friend's house and playing GT and MGS. I ended up with a console the next day. While MGS by itself may not be an enormous system mover in Europe and Japan, I think it would move a healthy amount of consoles in the US. I may be wrong, but that's how I feel about the franchise.