Recently I heard from Microsoft that there is now a new release model for hotfix rollups for BizTalk. The new model is similar to the service pack model (like with BizTalk 2006 R2 SP1) but is known as a Cumulative Update (CU). From what I have heard this is to provide greater frequency to the collective hotfix releases and a more predictable iteration for releases. This model is similar to what is being done with SQL Server and SharePoint Server. This new model of releases applies to all currently supported BizTalk versions including BizTalk 2006 R2 SP1, BizTalk 2009 and BizTalk 2010. Cumulative updates should be applied after running the older rollup of SP1 for BizTalk 2006 R2. It may seem like old news since BizTalk 2006 R2 SP1 is already at CU 3 but I had not heard many announcements about this or people mention CU 3 so I think most people do not know that the rollup release model was changed.
The BizTalk Developer Center Support page at http://msdn.microsoft.com/en-us/biztalk/aa937674.aspx mentions a little more about the new CU model, that the expected frequency is every 2 months, and that each subsequent CU will include all previous CU hotfixes. I was wondering what was the best way to find all of the latest CU releases and the way that worked for me was to search at support.microsoft.com for “BizTalk cumulative update”, so here is the link for this: http://support.microsoft.com/search/default.aspx?query=biztalk+cumulative+update&catalog=LCID%3D1033&mode=r. The released CU versions show up at the beginning of the search results, ordered, nice and easy.
At this time the CU releases are not being localized so if you are using a localized version of BizTalk you will need to install the English version of the CU. If you encounter any issues with the English CU release on your non English system you should report this as a bug so that a corrected localized version of the CU may be created.
BizTalk 2006 R2 SP1 CU 3: http://support.microsoft.com/kb/2286501/en-us