My gut says we'll never get another HDTA song, or at best maybe a single for a soundtrack or something. I'd love to be wrong, but it just feels like they're both more interested in NIN and scores than HDTA. Maybe Q is just more interested in other things than doing another album. Who knows.
All I know is that their songs just seem to work really well with the cold / grey / changing leaves vibe of fall, so I've been listening to them a lot lately and yes, wishing that more was coming.