I've read elsewhere that the current collection storage, either a dedicated MySQL or SQLite database, is going to be dropped in Amarok 2 in favour of the new libkmetadata for KDE4, which supports ratings, tags, etc.

Is this true at all? Moreover, if this is true, is there any automatic way of importing the old collection data from SQLite or MySQL into kmetadata, nepomuk or whatever it is called bundled with Amarok2 or thought-of at all?

Thanks!

I've no idea where you heard this... it's not correct reguardless.