I just never could bring myself to watch Last Exile. Dunno if I'm just spoiled by watching on DVD, didn't want to support the abortion of a channel that is G4FuckTV, or didn't want to fire up ye olde VCR again.
Producers of anime need to either learn to plan their series better, wait for the mangas to reach a good stopping point before adapting them, or get out of the 26 episode rut they're all in.
My most recent favorite anime series suffered greatly from the second on that list, bringing down an otherwise perfect show. All they had to do was wait a year on it to allow the next manga volume to wrap up the current storyline so as to come to a logical and satisfying ending point, but they blew it.
The only saving grace for this problem is the chance of eventually getting either an OVA or a movie out of the deal. But that's not guaranteed, as in the example I mentioned above.
As for why Gungrave hasn't aired yet, it's because it's still being dubbed. They've only released the first two DVD volumes so far....