The Cumulative update package 4 for BizTalk Server 2013 R2 is out, kb 3167705

Five of the fixes relate to the WCF-SAP binding, so if you are having issues with that binding this CU could be exactly what you need.

KB article number Description
3162562 FIX: SAPBinding constructor fails with NullReferenceException
3162564 FIX: WCF-SAP NCO Adapter fails when transport properties have spaces
3164725 FIX: IDOCs sent with BizTalk WCF-SAP NCO adapter are misaligned in SAP
3164728 FIX: WCF-SAP NCO adapter fails when saprfc.ini file contains comments in BizTalk Server
3164730 FIX: NullReferenceException is thrown when you change ConnectorType on WCF-SAP send port in BizTalk Server

Another fix is to do with HTTP Sending

KB article number Description
3165515 FIX: BizTalk HTTP send host crashes FireTransmitComplete during time-outs

However my personal favourite that will fix a painful issue during development is below. Having to remove maps from ports to re-deploy a schema is rather painful and this issue seems to crop up with each new version of BizTalk.  Hopefully we won’t see it back in BizTalk 2016

KB article number Description
3167704 FIX: Redeploy of schema referenced by maps fails after you install BizTalk Server

A list of all CU’s for all versions of BizTalk back to 2006 R2 can be found at kb 2555986 Service Pack and cumulative update list for BizTalk Server