The observer appears at the forum walking past Olivia when she is talking with Mr. Esterbrook.
The word that the glyphs translate to is "Cells".
The experimental medication that was injected into Clair Williams was a RED IV liquid (hint to "alternate universes").
The name of the assistant of David Esterbrook is revealed to be Elisabeth Sarnoff - the name of the Producer of the show "Lost", which was also created by J.J.Abrams.
Walter calling Astrid by the wrong name: Asterisk.