-The Suliban hand weapons have been seen before on Voyager, and probably DS9 too.
-The rifle the crewman was wielding in Sickbay was never clearly seen, but it looked a whole lot like it was modified from the Jem'Haddar rifle (especially the stock and handgrip).
-The tube Tucker is seen going up when he goes to find Mayweather looks like the Jefferies tube set from "First Contact", flipped vertical and adding a ladder.
-The ship that knocks T'Pol off the pod (which is odd, since the snow was hardly affected by the backwash) is a Voyager guest ship modified to add the thrusters & backwash. There's another ship on the lower level that I can't make out, but looks like another Voyager guest ship.
-The pointless little fence-like things the Suliban duck behind in the same scene are the pointless little fence-like things in the E-E corridors that Picard & Lily walk around in "First Contact".
-The console that was used to operate the forcefield in the Rigel basement has been seen on the Defiant and likely on Voyager more than once, as a Starfleet console with different backlit graphics.
That's all I can remember from last night. Anything else?
Mark