Microsoft have just released CU 7 for BizTalk 2013 R2
These CU includes 6 fixes.
I got rather excited when I saw that they had fixed an issue with the WCF-SQL adapter polling. However the cases the symptoms they describe aren’t quite the same as one we’ve encountered in BizTalk 2010 (so I don’t think this fix is going to help us even when do they get around to patching other BizTalk version). But it may fix things for others or spur them to look a bit closer at this adapter to fix other issues.
As per nearly every CU, it contains a iDoc/SAP/NCo fix and one for EDI.
There are also two fixes for two-way send ports (one deployment issue and the other a runtime one), and finally a TDDS/database fix.