Very non-standard Mac OS X UI. Not a bad decision, but it makes me wonder what Snow Leopard will look like.
Although I’m not so sure about that reload button in the URL field. That makes sense on the iPhone, since it has a limited amount of screen real estate, but not so much on a desktop browser.
And there’s no progress bar, just like that other browser.
Edit2:
The font for the titlebar appears to be smaller and thicker:


