Woah. Beep. Beep. Back up .
ROM Planetarium is going to be redeveloped by someone called DS+R?
It's not quite that famous a name. Most readers won't recognize them as "starchitects"… which will make it that much more difficult to guess, so I'm trying to be a well-intentioned wet blanket here: I'm afraid that when this is revealed that people will be disappointed…
So I'll tell you now, it's not any of the names guessed so far, and as a bonus, add MVRDV to that list.