Clemens posts his 2-sentance definition of Indigo:
Indigo is the successor technology and the consolidation of DCOM, COMPlus, Enterprise Services, Remoting, ASP.NET Web Services (ASMX), WSE, and the Microsoft Message Queue. It provides services for building distributed systems all the way from simplistic cross-appdomain message passing and ORPC to cross-platform, cross-organization, vastly distributed, service-oriented architectures providing reliable, secure, transactional, scalable and fast, online or offline, synchronous and asynchronous XML messaging.
From what I have read from the keynote demos, it sounds like it was great to actually see this in action. Nice to see all these technologies combined together. Also, from Clemen's posts last week, it also looks like what we are doing now (with ES, .Remoting, etc.) will still hold true with Indigo. That's very good news.