You might be able to squeeze a little more storage into those Blu-ray discs soon. Sony and Panasonic have been working on increasing the maximum capacity per-layer from 25 to 33.4GB, and the new version might be ready for market in the near future.
Hopefully this doesn’t mean you’ll have to buy another drive, and there’s one hell of a lot of science content involved (regarding something known as an i-MLSE), but the gist is that there is new technology coming.