The Blogical.Shared.Tools.BizTalkBuildTasks includes three tasks for deploying BizTalk 2009 assemblies to BizTalk.
Undeploy Bindings - Since we are going to redeploy the solution, we need to remove all previous assemblies and artifacts.
Deploy Assemblies - This Task can optionally be disabled, in case you just want to undeploy. The bindings files will tell us to which BizTalk Application an assembly should get deployed to. if your build results in assemblies that should not get deployed to BizTalk, then these won’t get deployed since they are not included in the bindings files.
Import Bindings - This is the last custom task to be executed, and will create all the port bindings