Best MacBook for Video Editing? (Budget: 1500 euros / 1700 dollars)

I'm a film student, and landed a nice internship starting January 2014. (Very excited)

Before I begin though, I need a macbook.

I'll be doing quite a bit of serious video editing on it, so I want a smooth playback on HD footage with color correction. But I won't be doing the real pro stuff with higher than HD resolution or multicam support. I'll also use AfterEffects, Photoshop, maybe Speedgrade, etc. This macbook will really be to bridge the internship-filled gap between student life and my first professional paycheck. 1500 euros/1700 dollars is my absolute top.

I'm torn between a mid-2012 13 inch MacBook with an i7, and a retina MacBook 13 inch with an i5. I've heard bad stories about the latter, concerning its lackluster GPU, but the former has the same GPU and I can always scale down the resolution, right? I'm curious to whether a newer i5 and generally newer architecture will outperform an older i7. My current PC has a kick-ass GPU (GTX 670 Ti) but it hardly ever fires up. CUDA and GPU acceleration if a bit overrated if you ask me.

Then there are also older 15 inch macbooks that have dedicated graphics, and tons of options of upgrading an older machine to 16 GB of RAM or GPU upgrade... The current retina 15 inch seems perfect with its dedicated GPU but its too expensive- will it be cheaper by christmas? Should I wait for the new line of macbooks maybe?

The small SSD is not an issue cause I'll be editing off external HDD's anyways. Thunderbolt is a plus for that reason.

Lots of options! I'm hoping to hear from some freelance video editors who maybe use a macbook as their second machine. Has anybody used the new retina 13 inch for editing? Is it a disaster, Or just OK?