Funny looking dudes with blue skin and two "cute" moving antennas sticking out of their forehead.
The leader Andorian was played by the same guy who played Weyoun (spelling?)
We also found out that Vulans are big fat stinkin' liar who hide a GIGANTIC spy station under some supposingly monastery to monitor the Andorian even though there's a treaty that forbid the Vulcan to do so...
That's about it, and oh yeah, Archer got his ass kicked quite a bit in this ep.
All humor aside, we've already discussed the updates on the makeup for the Andorians (comparing the two instances from TOS and the one from TNG). I think that the update on the makeup is pretty good; the new forehead piece is not just a new series of ridges. It's just an extrusion that blends quite nicely into the antennae. And, yep, Jeffery Combs (formerly Weyoun and Brunt from DS9) stars as the lead Andorian character.
As far as the rest of the episode, I am curious about some of the other specifics. Can we get some more detail on the Vulco-Andorian Treaty and the circumstances and summaries of dialog involving this sensor platform? It seems to me that this could be a continuity problem; it also seems that it may not be depending on how it compares to Tuvok's undercover work in "Caretaker" or Spock's intentional deception in The Wrath of Khan and The Undiscovered Country.
Also, is this episode more centered on the crew of Enterprise being thrust into this dispute between the Vulcans and Andorians or is primarily a Vulcan/Andorian episode with the Enterprise crew showing up when necessary?