There's a summary of the status of the Herculaneum Scrolls reading project in the latest issue of the Economist (where else?).
It's behind a firewall, so a quick summary of what they're saying.
They scanned four scrolls. The data from one wasn't very good, and they detected ink (and some writing) in one, but not in the other two. This may be because the last two were blank, or because they were written in a different ink.
They've now scanned 21 additional scrolls with a much higher resolution scanner, and are starting work on the data.