fflint - I certainly hope so! I wonder what the vacancy is at 555 Mission. If they've filled most of that, it could also look good to lenders since that was built on spec (though a few years ago now) and is right next door.
1977 - in the case of 535, technically they don't even need to "break" ground, just scoop up a bunch of rocks!
That is really great news for the museum. Imagine the variety of exhibits they'll have access to with that relationship. Also, don't forget that 706 Mission has a thread
if you want to post that bit of good news over there too.