The USS Yamato, the ultimate red shirt ship.
I really hated how what was left of the saucer seemed to head right for Enterprise and basically smushed against their shields. eww.
Actually, I'm pretty sure the Yamato's saucer did NOT impact the Enterprise's shields. We saw how the bridge shook when a piece of debris hit them. I think it's safe to say that if the MUCH LARGER saucer had hit them, we would've noticed.
This episode also introduced us to the barely touched upon Iconian civilization. The idea of a very advanced race who could travel anywhere in the galaxy by merely stepping through a portal was quite interesting. Why did this advance civilization just die out when they had so much at their disposal to survive? Could an alien race we've seen in other series like DS9 and Voyager be descendants of the Iconians? I'll always miss that story potential.
The Iconians did pop up again (sort of) in the DS9 episode To The Death
Well, at least their gateways did.
I agree, I'm suprised they never revisited them properly to find out who they were though.
IIRC, the episode states that the Iconian homeworld have been devastated millennia ago by orbit bombardment. (Wonder who did that, BTW? The Promelians? The Menthar? The Tkon?) However it's implied that at least some of them used their gateway to escape to other worlds where they integrated themselves into society.
We never got a clear indication of what that gateway can really do. If an enemy fleet attacked them, could they teleport a couple of grenades into the hostile ships' engine rooms?
Ultimately, though, it would open up too big a can of words for future episodes to give anyone that kind of power, so, as with "To the Death", the only way for it to end is with the gateway being destroyed.
As for why it was never followed up, well not to long after "To the Death", we had the premiere of another
popular sci-fi series with a similar premise.
One last observation, I wonder if the destruction of the Yamato, plus the numerous civilians who surely died at Wolf 359, caused Starfleet to get it in its head that having a bunch of families and kids on starships is generally a bad