I don't think backlit keyboard is really important, and 2GB of RAM difference shouldn't cost that much. imo you're just paying for a "pro" tag behind. And those prices are in USD.
A normal notebook with those specs don't cost as much. I'd still get a normal Windows notebook over a Mac for the price difference. I've used my friend's Macbook before and it's nothing special.
As for netbooks, I'd say they are powerful enough lah, maybe not for heavy Photoshop work but they should be fine.
My Acer Timeline notebook (ultra portable notebook, not netbook) that I got last year only has a dual core 1.4GHz processor and Photoshop works fine for me...Only tried basic adjustments (exposure/curves/levels) and some noise reduction though. And the batt lasts a good 8 hrs as advertised if ur just working on Word docs with the lowest brightness (even though it's quite bright already)