You can now download from MSDN the full suite of BizTalk 2010. It came up today.

BizTalk Server 2010 Branch Edition (x86 and x64) – DVD (English) 660 (MB)

BizTalk Server 2010 Developer Edition (x86 and x64) – (English) 552 (MB)

BizTalk Server 2010 Enterprise Edition (x86 and x64) – DVD (English) 965 (MB)

BizTalk Server 2010 RFID Enterprise (x86 and x64) – DVD (English) 81 (MB)

BizTalk Server 2010 Standard Edition (x86 and x64) – DVD (English) 965 (MB)

Host Integration Server 2010 Developer Edition (x86 and x64) – (English) 152 (MB)

Host Integration Server 2010 Enterprise Edition (x86 and x64) – CD (English) 321 (MB)

Interestingly the developer edition which is a smaller download, actually contains the same contents as the Enterprise Edition.