1.	The breathless press reports say that this technology is revolutionary, and I believe it is, but not the way they say it is.
2.	XML-RPC, emphatically, does not enable new applications. Anything you can do with XML-RPC could be done with any of the previous technologies that allowed applications to be controlled externally: COM, Apple Events, CORBA or CGI. In their day, these protocols were revolutionary because they turned applications into toolkits. Spreadsheets and page layout programs became platforms because of these technologies, spawning new developer communities, and giving new power to application developers and their users. XML-RPC is revolutionary in this way too, but it's not a new revolution, it's a replay of a revolution of the late 80s and early 90s.
3.	If you're looking for something new here, it's that XML-RPC turns the Internet itself into a scripting environment. It makes it safe to not use the programming tools and runtimes supplied by the operating system vendors. Unlike the previous technologies, you are not locked into Windows, Mac, Unix or Java. There's a good chance that your app can communicate with any other app, no matter where it runs. It also makes it safe to choose a minority platform and communicate on equal terms with apps that run on previously dominant platforms. It undermines the hegemony of any platform that seeks dominance. This is why it was so courageous for Microsoft to take the lead in this technology. It's also why Microsoft is second-guessing this vision by promoting a Common Language Runtime, which is totally contrary to the philosophy of SOAP and XML-RPC, and should be approached by developers who value independence with extreme caution.
4.	If XML-RPC achieves its promise, it will probably not, on its own, deliver any new products or features to users that wouldn't have been possible with previous connective technology. However, it will create new opportunities for small independent developers to come out of left field and create new applications that the Big's would never be able to get through their lugubrious development processes.
5.	Yet the hype surrounding web services carries the opposite message, people who are supposedly experts in this area look to the Big's to produce the innovation, as if they have any track record of doing that. They don't, for good reason. I watched Microsoft's internal process chew up XML-RPC and spit out SOAP, a protocol full of second-guesses and hedged-bets; compromises that make it so complex you need to have a full-time engineer on board to keep up with the latest schema; where interop lasts months, instead of forever, as it must if the technology is to mean anything at all. The process of SOAP is sick, because it's dominated by conflicted big companies. Meanwhile XML-RPC keeps chuggin along, doing what they hope to do someday when they are finished, which seems can never happen.