personally, I think that if the songs are recorded, and if they're actually good enough for release, why not release them all? if it's good music, I'd love to have more of it. it may take more time to become familiar with all of the songs on both discs (twice as long as a normal album, presumably), but I think it would be worth it.
again, this is all contingent on it being a worthwhile double album. if it's just saturated and diluted crap spread across two albums, obviously that's not preferable. but there's no reason to turn down a double album when it could easily be well worth it.
