"The fifth public alpha build of Firefox 3 has been officially released. The new alpha build, which is codenamed Gran Paradiso, features early components of the revamped Places system, a cohesive storage framework that will unify bookmark and history storage. An earlier prototype of the Places system was tested in early Firefox 2 alpha (Bon Echo) builds but was removed because it couldn't be completed within the Firefox 2 release timeframe.
"The current implementation of the Places system is still a work in progress, but the final version will support features like bookmark tagging, full-text indexing, extended metadata search, built-in syncing functionality, and support for exporting bookmarks in a broader number of formats..."