Some of the decisions [...] are simple business decisions that are determined by who your target audience is.
1. If you want a great experience for .NET/Java devs, you’ll typically publish schemas (through wsdl) and support SOAP.
Hmm, "business", "audience" and then "developer" just don't flow for me. The market for true Web applications are users, not developers. Developers using early binding procedural languages will be a shrinking market - not a growing market. Those who build for themselves are the new 'developers'.