What application exactly would you like skinned? Web wallets are nicer in terms of usability. BitcoinQT definitely needs a better UI/UX component. Mobile apps are very simple as well.

Of course, there is a strong upgoing trend in web design and experience - flat colors, more CSS3 animations & effects, but it is all within the HTML5/CSS3 frames.

Basically, we need a good cross-platform client with all the HTML5 features (webkit). But what about the security component in that case?