Release 2 comes with this new feature:

CD Ripper - when showing Review Metadata page will indicate if cannot show for various reasons (metadata came from HDD cache, or PerfectMeta is disabled)

Personally, I don't like it: the Metadata review window is much more convenient to edit and enter metadata over an entire CD, so it's an inconvenience to me not to be able to use it when no metadata is available on the Internet.