Maybe. What mechanism do you have to keep the drive in once you put it in? Is there a latch or something?

 The SATA port itself is very very snug. To actually be able to have the drive slide in/out, requires putting in some spacers, or something that will 'pry' the bottom cover away from the laptop itself. The drive is very snug against the black plastic sheet (which houses the keyboard). The one you got is different, mine had metal go around all the way, rather than a frame.

 I just watched your video again www.pinkbike.com/video/277644
It's pretty cool. I have to see if I can figure out if my caddy if i can mod it like yours.
Mine is this unit.. eshop.macsales.com/shop/drive_bracket/datadoubler

 http://www.newegg.com/Product/Product.aspx?Item=9SIA1KT0EX2714 If you look at the pictures, it's just folded piece of metal. I shoved some lego plates in there to make it 'taller' so the drive itself can slide more smoothly.

Because yours is positioned all the way to one side (where as mine is in the middle), it might be more difficult in finding a way to add spacers on both sides, especially because that is next to one of the screws that screw in the bottom aluminium plate of the MBPro.

By itself it is fine, but to properly have the drive slide in/out smoothly, you'll need to add some spacers.

 Radek, keep in mind that regular SATA connector has a rating of only about 50 connections, not sure what the actual failure rate is, but I know it's reasonably common with hotswapping SATA drives...