the thing is, to implement realistic looking cockpits it should be possible to move hud elements around (or disable them completely, depending on the cockpit model).
That's the ultimate goal obviously, to allow the creation of both realistic flight-sim style cockpits, as well as more arcade-style cockpits.
In the meantime though, hud_gauges.tbl could be expanded to allow for profiles that would allow different ships to have different HUD setups. And adding more gauges is just something that is (or should be) on the todo list. I'd add them myself, but I honestly don't know what's missing, so a list of what doesn't work would be a help.

Plus I think that Backslash was/is working on hud_gauages.tbl stuff, so maybe he has already gotten some of this worked out.
Two questions:
- What about seeing damage to your own ship from the cockpit? How will the new method handle that?
- I assume the new system will allow one to look around the cockpit, and use a padlock view. What the status on that?
a) Damage can/will be mirrored on the cockpit model based on what the player ship has. This is sort of a given in order for it to work and be believable. You actually have far less ability in this respect with the current way that show-ship works.
b) The new cockpit setup won't actually allow you to do that, it will just make adding such code finally worth it.
it would probibly be a good idea to not render the lowres cockpit model (any submodel named cockpit_interior) of a player ship if it has an external high detail cockpit model and the view is internal. id still like show ship to be valid though. cause sometimes theres external geometry and weapon models of your ship you would like to show.
The old show-ship method will be dead, and you aren't going to lose anything, so get over it already.

The cockpit pof can have anything that you want on it. The code will simply mirror as much as possible about the state of the player ship on that model, whether it's damage, submodel animations, external weapons, whatever. The only difference is that with the cockpit pof you won't have to pull any punches with regards to detail. Add your polys and make it look as good as you want. It's only ever going to be rendered once per frame, so you simply don't have to deal with all of the crap that you have to go through to make a regular ship model work well.
Plus, having the cockpit as a submodel in a ship incurs a performance penalty (just as any submodel does), so making as much of a ships cockpit part of the main hull as possible will make a ship render faster/more efficiently. Simply having the cockpit as a submodel hurts far worse than any potential waste of polys.
If you use "show ship" and have the cockpit pof entry specified, then it will only ever use the cockpit pof, period. We aren't going to hybrid anything, because as I said earlier, the current method is simply stupid. There isn't necessarily a reason to remove support for it, but I'm most certainly not going to maintain support for it working together with the new features that are coming in the future.
And the reason that "show ship" would still be required (in case someone askes) even when a cockpit pof is specified, it's because that way we can have support for a species default cockpit too, but still allow individual ships to make use of regular hud_gauages.tbl rather than a 3D model.