Brandon and Ganesh Amle have been working pretty hard on their patterns. Below are the two I already mentioned and another three to wet your appetite.

The adapter migration toolkit (BizTalk Server 2002 compatibility layer in BizTalk Server 2004 for adapters should be out in the next day or so). I'll let you know as soon as it happens...

Biztalk 2004 Synchronous Request Response with Data Aggregation Pattern

http://www.gotdotnet.com/Workspaces/Workspace.aspx?id=21f5adfa-17de-48df-bed3-17a3f706a5b4

Biztalk 2004 Asynchronous Request Response with Data Aggregation Pattern

http://www.gotdotnet.com/Workspaces/Workspace.aspx?id=8ae8d95d-465a-439d-a209-e4d86f0f54d9

Biztalk 2004 First in First Out Pattern

http://www.gotdotnet.com/Workspaces/Workspace.aspx?id=3f2e09c9-d63b-423d-ac03-37eb3596dbb2

Biztalk 2004 Component Retry Pattern

http://www.gotdotnet.com/Workspaces/Workspace.aspx?id=2fa6b559-b24d-403e-b28f-e8a89262963e

Biztalk 2004 Interruptible Business Process Pattern

http://www.gotdotnet.com/Workspaces/Workspace.aspx?id=f5426714-c2b7-4e34-85ac-b1237ad47057