Choice in software
Dan, choice in software is what matters, not choice in formats.
Having a small number of formats keeps the market friendly to small independent developers. And that's where real choice comes from. Choice between Google, Yahoo and Microsoft will not turn out to be choice that empowers users.
When a big player like Google forks, they provide the excuse for Microsoft and Yahoo to do the same.
Each of the BigCo's will create their own format and eventually you'ill need a Microsoft aggregator to read Slate, and only Yahoo's aggregator will read their news service.
We've just taken the first major step toward the Syndication Wars. It's still not too late for Google to step back. But it's looking less likely.