If you truly want a Mac, I'd wait a bit, as the new lineup is rumoured to be announced in a few days. For what you want to do, I'd actually go for the 15" Mac, as it has (apparently) a higher gamut screen which will help you with your photo editing, but the current model's glossy screen while beautiful are too shiny for photo editing. The new models might have an option for a matte screen. I myself bought a 17" Macbook Pro with a matte screen because it was the only laptop that fit my needs of a big screen, high colour gamut, high resolution (1920x1200), power & portability. It's a dream to use for photo & video editing, and the thin & light form factor was what sealed the deal for me - no other 17" laptop came close to the 1" thickness & 6.6 lbs weight. I do not miss Windows at all. It's not perfect by any means, but it's an impressive machine. Also, poke around in the refurbished section of the Apple Canada store. There are good deals to be had there.
Cnet has a very favourable review on the Asus U30Jc-A1 here:
http://reviews.cnet.com/laptops/asus...?tag=mncol;lst They did complain about the weight of the Asus, which I thought was excessively heavy.
In my opinion, a 13" screen is too small for photo & HD video editing though.