I imagine the initial rush of apps will look inconsistent. In a few months they'll hit upon the idea of making a standard set of CSS classes that apps can use

I imagine the initial rush of apps will look inconsistent. In a few months they'll hit upon the idea of making a standard set of CSS classes that apps can use to blend into the style of the host site. Hats off to google et al if I'm wrong and tomorrow's announcement already includes CSS guidelines. This is exciting news.