See the mailing list for details. A new snapshot of the PalmOS version is available from the download page. This version is a major rewrite, so much functionality is not present, but you can see parts of the new interface. See the mailing list announcement for more details. In this new desktop snapshot, you can create several minds and link between them.
More details are available in the mailing list archives.
A new desktop snapshot is available. In this version, you can open multiple minds at once and open multiple windows. New snapshots for both desktop and handheld are available. No new features, just the new name.