This is a new trick I've only just picked up while browsing Slashfood. A contributor named Marisa made a Thanksgiving post that I recalled and looked up for Christmas turkey use.
Now, of course, you can just go read her post (please do, otherwise I'd just be copying everything she said), but her and I e-mailed back and forth a few times and a few things came up worth mentioning. I've used uncoated pans (the new saute' pan that Karen just picked up for me, pictured, is great for containing the potential huge mess) while Marisa, I found, used a nonstick pan. I'm pretty sure this is the reason my flour toasted so quickly (12-15 minutes vs. 30 to 60). Also, I just have to say if you have a badass flat whisk you'd normally use for deglazing...that's what you should use.
So, true to the original story, the gravy we made for Christmas dinner was fantastic. With so much flavorful, colored flour, you can expand your turkey juices more and have more gravy then you normally would, and the pre-cooked flour required little cooking to remove the "doughy" flavor that you normally need to work out.
This 2ed batch I just did is for some shrimp gumbo I'll be making tomorrow. A nice dark roux is a tradition of this dish, and this should give me a nice head-start.