Earlier this week I was informed that Microsoft BizTalK Server 2010 has passed compatibility testing with Microsoft Dynamics AX 2009 SP1. See http://blogs.technet.com/b/dynamicsaxse/archive/2011/09/22/microsoft-dynamics-ax-2009-sp1-is-compatible-with-biztalk-server-2010.aspx for more details.
I would recommend that if you are using BizTalk Server integration to at least have Microsoft Dynamics AX 2009 SP1 Hotfix Rollup 7 Kernel installed as aminimum on all your AX systems. This Kernel build contains the following AX BizTalk adapter fixes and enahnacements:
2389818: “Requested Service not found” error message when you use the BizTalk connector adapter in Microsoft Dynamics AX 2009 Service Pack 1
The BizTalk adapter cannot handle response messages from Microsoft Dynamics AX 2009 SP1 on a successful delete service action or a successful update service action
and other kernel updates from previous rollups.