This is a major release with significant changes to the program and database structure aimed at providing a solid, flexible foundation on which to build in future.
While there are no known bugs it would be a pleasant surprise if none were found and I fully expect there to be further fix releases in the 2.0 version - if nothing else there are a large number of new translation strings required.
Note that after upgrading most of the configuration is stored in the database and can be accessed from the preferences / admin page (/admin.php)
Apart from creating database.inc.php the rest of the existing configuration should carried over by the upgrade. There are various new configuration parameters which are recommended to change but not essential.
It is highly recommended to install with the dojo functionality enabled as described in the INSTALL document and configured by the admin page using the layout drop down See the CHANGELOG for a more comprehensive list of changes - I'm afraid it's not detailed documentation but hopefully it's sufficiently obvious to work out what's going on - I'll try and answer questions in the forums.
Thanks to Ian for all his efforts bring about this major release!