I agree, this does appear to be the trend. Google also has indexing support for AJAX pages (http://code.google.com/web/ajaxcrawling/index.html http://code.googl

I agree, this does appear to be the trend. Google also has indexing support for AJAX pages (http://code.google.com/web/ajaxcrawling/index.html http://code.google.com/web/ajaxcrawling/index.html) so it's not hard to make a single-page app that is indexable by Google. My concern is that we are building all of this on top of HTTP, which wasn't really meant to be used this way, and there's bound to be some caveats from that. One potential pitfall I can think of is cookie management - the JavaScript APIs to manipulate cookies is very poorly defined easy to make mistakes while using. I think this is doable but we need to tread softly to make sure that we don't introduce new classes of vulnerabilities.