At the very least, separate models and texture jobs for different percentages of hull damage would be interesting. Then you could see just how badly a ship is doing, even if your subsystems are completely gone. The problem with this is that you'd have to make the damage uniform --- if its too localized in one given spot, you run the risk of two damaged ships side by side with burn marks and missing chunks of hull located in the same spots (which would look stupid). So you'd have to take the hull and just make it uniformly look more and more like crumpled paper rather than Swiss cheese.
This system would work best on smaller ships where you're not apt to notice as easily --- transports, fighters, etc. A subsystem "chunks break off" setup is ideal for capital ships and other big things --- but it'd have to be heirarchical to prevent outlying chunks from "staying a part of the ship even though theyre floating completely outside it" --- destroy enough parts around one part and the other part must go, too. Complicated...which is probably why we don't have this yet!
However, there is one alternative idea:
Imagine if a GTCv Deimos blew up, but most of it survived the explosion -- and the model were split in half, revealing decks and wires and tubing and etc.
What do I mean?
HTL ship debris, of course! ^^ Why the hell not!? As before though, would have to make sure that damage details aren't too..."recognizable" to make sure that you don't kill realism, but it'd be well worth it. Before, you could sit next to a capship exploding, take the shockwave, and the debris was just eyecandy. If a Deimos corvette blows up in front of me, dangit, I want a huge chunk to hurtle at me so I can have something to DO when it blows up. =p
