I dunno about anyone else, but I think Harmattan's "fade into the OLED" aesthetic is pretty timeless.

Glacier is suposed a mild rework of Harmattan - moving out some half-baked ideas, and taking some inspiration from Android and WP.

Of course, we can't radically change Harmattan as it is now
If I were you, I'd start on darkening the UI, continuing with the high-contrast thing Nokia's got going on in the Settings app.

The bottom menu bars in the Contacts and Messaging app look atrocious, and I've been wanting to change them out for some time now.