We learn a little bit of background on Will & Grace's college dating days and Will & Michael's 7-year relationship.

Chris Potter, who plays Micheal, also played another gay character on "Queer as Folk" who was romantically involved with the character "Micheal".

Jack: I can't pee in public bathrooms.
Will: Why not? You do everything else in them.

Will: I've got my chimp on a NordicTrack. He gets in his little suit, hops on, watches the TV. He loves it. But ... enough about Jack.

The door in the middle of the hallway it now an apartment, despite the fact that a map of the building next to the elevator shows it as a supply closet, and that technically Will's small bathroom is behind it.

The chair that Karen sits down in and turns nice is the same that she's been sitting in since the show first began.

Will implies that he and Michael split up at the end of 1996, but when the Will & Grace show started in 1998, he said he'd only just split up with Michael.

Will: I--I--I plucked my eyebrows so I wouldn't have that scary Peter Gallagher thing going on.

Peter Gallagher is notorious for his bushy eyebrows.