9.4.1 R2 is a re-release of 9.4.1. Its major functional change is in the installer, where it now re-includes installation of JBoss and adds (optional) automated database creation. So for the most part, it is a repackaging of the prior binaries and provides install improvements, hence the "R2".
9.4.1 R2 also, however, includes a renaming of the product from its prior multiple names (Workplace Portal, Cloud Portal, Service Portal) to a single unified name, Cisco Prime Service Catalog. This new name appears on the portal screens, and there are other look and feel changes to better align with Prime user experience standards.
Since most customers change the name of the portal and its colors to look like it came from their company, there will be no reason for existing customers to upgrade from 9.4.1 to 9.4.1 R2. However, by using 9.4.1 R2 for new installations going forward, you will have the benefit of faster installs and the new branding.
I'm not sure where the official documentation is available for partners. I'll leave that part for others to answer.
The release notes points out many bug fixes. Shouldn't we care about installing it on top of a current installation ? It would be great if I could install it on top of an existing database, choosing not to install a new jboss. A documentation on its installation would be appreciated.
Thanks in advance.
9.4.1 R2 and 9.4.1 have the same set of bug fixes incorporated, so if you already have 9.4.1, then there is no reason to reinstall.
Just to reiterate - it is unnecesary to upgrade from 9.4.1 to 9.4.1 R2. There are no changes to the run-time engine and databases between these two releases. All future patches for 9.4.1 will also be applicable for 9.4.1 R2, and vice versa.
The install guide for 9.4.1 R2 is available on http://www.cisco.com/en/US/products/ps11927/prod_technical_reference_list.html.