I don't agree with your premise or conclusion. Its far easier for a website to just publish a dead XML file that any client can read at their own pace, as frequ

I don't agree with your premise or conclusion. Its far easier for a website to just publish a dead XML file that any client can read at their own pace, as frequently as they would like. Also, anyone can create a pub/sub 'middle man' that can implement a push system for clients who want that. You can have the best of both.