Underground Lava Rivers

After seeing recent snapshots for the upcoming Caves and Cliffs update, I've fallen in love with the new caverns. The new blocks and flooded caves look stunning. After seeing a few lava falls along the edges of the caverns, especially below y=0, I had the idea for lava rivers. In the new snapshots it feels like there's been a lack of lava down in the caves, with lava only appearing in closed off pockets of air. This is why I'd love to see lava rivers spawning along the bottom of caverns. Not only will it add a bit of atmosphere to the dark and dreary caves, it'd also add a touch more danger. Especially if a creeper spawns behind you and knocks you in. So I think the possibility for lava filled caves and lava rivers to generate would be really interesting to see.