A lot of changes in this version of Viewer2. It is possible that your existing database won’t be compatible and dbtool certainly isn’t. Unofficially, the upcoming release is something comparable to a 1.0 release.
What is new? The interface is more mainstream in that there actually are clickable buttons (you can still use the keyboard shortcuts, too) and some ugly things have been deuglified. Also, rounded corners all over the place.
The search has been improved in speed and features. Viewer2 now also has a thumbnail cache which speeds up loading of views especially if there are huge images that need to be rescaled each time a thumbnail is needed. Viewer2 can now look in the IPTC metadata included in some image files and suggest tags based on the information.
As I said, there really are a lot of small (and not so small) changes and I have probably forgotten half of them. I hope the forthcoming demo videos will help everyone catch up (also I secretly try to make things logical enough you don’t even need to read the manual for basic use). The video below is a small demo, for proper help see the manual.