Styles in shared UI (Xamarin.Forms)

Hi,

I read in http://forums.xamarin.com/discussion/25612/xamarin-forms-1-3-0-technology-preview

Xamarin.Forms from October 2014. "Support styles in XAML and in code"

Please let me know where I can read details about it?

How advanced is styles support? Is it allows me to build something like button with rounded corners, with image icon and gradient background? Or I still have to use custom renderer for that?

Regards