A month after the Indigo 'Kimono opening' at the PDC there's still a lack of clarity about what Indigo is, how it relates to other messaging technologies and what's the best way to start developing applications today.  While a lot of this was covered at the PDC my perception is that some of the message hasn't been ack'd successfully from the audience.  [Update: See my more recent post 'More on the Microsoft Messaging message' for some answers to these questions]

The Longhorn DevelopMentor mailing list had an excellent exchange yesterday on Indigo, which has lead me to highlight some areas where I'd like a clearer message:

• What's the relationship between Indigo, MSMQ, BizTalk and SQL Server Service Broker?  When and where is each technology appropriate? (Thanks to John Cavnar-Johnson for highlighting this)
• How does MSMQ fit into the Indigo longer term picture? Is MSMQ for within the Enterprise or will it focus more on outside the Enterprise messaging?
• In terms of EAI technologies, where should we look for this functionality - Indigo or BizTalk?
• Which parts of Indigo are going to ship in Whidbey and which bits will come in Longhorn?
• Given that the last version of WSE will be wire-level compatible with Indigo and that a future version of WSE is likely to support WS-ReliableMessaging, what are the benefits of Indigo other than the simplified programming model?
• Indigo is committed to supporting WS-* standards and interoperability, but what extra functionality will be available if the whole environment is made up of Indigo boxes?

I'm  know some of these were addressed at the PDC.  I'm still digesting some of it (for example, the PDC DAT406 presentation on the "Yukon" Service Broker shows how MSMQ, Indigo and Service Broker are positioned, though not BizTalk).  Other questions I'm still researching.