Ted Neward gave the keynote at our WS-Interoperability Day even today.  Here are some of the points he made:

• It's important to learn from the past, in terms of previous distributed computing approaches, when looking at Service Oriented architecture and web services.
• One of the key things that made HTTP a ubiquitous approach to solving interoperability problems was that it was simple.  For me this highlighted the fact that it is essential that good developer programming models be developed over the top of the WS-* standards so that it's simple for developers to take advantage of the functionality without necessarily having to be a plumber. 
• It is important that vendors continue to work together and not start developing their own non-standard features.  Ted mentioned that vendors are currently being driven to ensure compatibility in order to make money from the new approaches, but once a market it established they may start fracturing away by adding their own non-standard implementations.  Dare covered this in his post detailing the SQL standards.
• Ted made the point that Objects work better when they are deployed together because they need to talk together.  Good objects are well factored and make a lot of calls.  This means that the same techniques does not extend well to situations where objects are distributed.
• The fastest call that can be made to a network is around 1000 times slower than a local in-process call.  This can raise to 10,000 times slower when the network is involved.  To illustrate what this means, Ted used the analogy that this was similar to his 20 minute commute to work taking 70 days (his math).
• SOA is just a new way to get developers to listen to the worn-out message that  'Distributed Objects Don't Work'
• Interoperable systems work best when the architecture is built from the centre out.  If you start at the .NET and work towards Java for example it's likely that you'll find you've implemented something that is incompatible.
• The problem with starting from the inside out is that WSDL, which provides the definitions, is hard to work with and you really need a tool to author it.