This sort of things makes me wonder about the difference between business code and UI code and the effect of splitting them. Right now the argument is that it'

This sort of things makes me wonder about the difference between business code and UI code and the effect of splitting them. Right now the argument is that it's too expensive to maintain two separate user interfaces. But as more and more pages start moving all their business code behind web services that might change (since the cost to maintain a UI would go way down) You could even get situations where third party companies agree to maintain an older interface while paying the company a small cut.