When will Lana Del Rey release another album?

Yes!

Not for a while though. I'm a massive fan and I've listened to most of her interviews etc and her plan goes something like this:

She's releasing Cola as a single with a music video in the next couple of months.

She goes on a European tour may time, by then she wants to make a new music video which combines Gods and Monsters with Bel Air.

She's also helping to make music for the film, "The Great Gatsby" due for a release in May.

Then as for the next album, she's probably going to release in late 2014. She's already planning it, she's commented that she wants the first song and the last song on the record to be acapella tracks (no instrumental).

So yeah, she is releasing a new album and she's planning it already - but it won't release for another year and a half I'm guessing. She has lots of other exciting stuff planned in the meantime though so :)

Oh and -- the unreleased tracks will NEVER be on an upcoming album. You may not know but they've already been released on other albums, just years ago and when she was less known. Since then they've been taken offline and stuff. So I don't see why she'd release them again if she's already released them but maybe :P