I popped in on Sunday. It's maybe 50% bigger than the Yorkdale store, but still not a flagship type location along the lines of the SoHo or Michigan Avenue stores.
It's months away. When I was there last week, none of the hoardings around the few store locations that are being renovated had any Apple markings on them, and usually those are put up 3 months ahead to build anticipation.
Gawker.com has this to say this morning about the new 5th Avenue Apple store:
"Ohmahgah, the NEW APPLE STORE WILL OPEN TOMORROW THANK YOU LORD STEVE! Curbed has a sneak peek inside the new 5th Avenue cube, and reportedly the cult leader himself will be present when the store opens. Now wipe that drool off your face and work on losing your virginity. "