Disclaimer: All information assembled in this posting are collected from the session titles and abstracts for PDC 2003 and other official information from other bloggers. I am not violating anything here :-)
The magic word 'Indigo' has been speculated (very weirdly) about by many unauthorized and authorized, because very involved, personsin blogosphere. For now, it seems like Indigo has the aim to be an integrated, extensible framework for distributed applications on the .NET platform - but with support for a wide range of distributed topologies like in-process, cross-process, intranet and Internet. Following the big Web services wave, Indigo is based on the WSA (formerly known as GXA) protocols and specs to achieve the best possible interoperability with other vendors like IBM and other partners. Maybe Indigo will finally achieve it to make it easier to build distributed applications by supporting a wide range of messaging patterns (think of request/response, asynchronous, P2P, etc.).
Messaging bus - this seems to be the most appropriate word to apply here. We actually do not have to be visionary to recognize that Indigo will be all about messaging, messaging, and perhaps ... messaging. We should expect to see intrinsic and easy to use functionality for
Call context instead of stressing on the concept of object context
Contract based loosely coupling (with extensibility and evolvement in mind)
Managed classical OTM functionality as can be found in COM+ today (read: transactions and friends)
Several stacks (or better [sub] frameworks?) like networking, security, messaging, serialization and the like
... a lot more of cool and interesting stuff we will all hear about in L.A. ...
Indigo should be delivered as part of Longhorn (?) and could be an internal part of the system as COM+ is today part of Windows 2000 and higher. So for now it looks like all the apparently unrelated information that stumbled through the blogging world in the last few weeks to months about schemas, type, versions, loose coupling and all this stuff have had the big plan in mind ...
We all should be very excited and looking forward to L.A. Cheers.