There's a great set of articles (part 1, part 2) from LWN discussing some of the processes and issues that were used / encountered when attempting to bootstrap a build environment for ARMv7-a hard float. Turns out, Fedora didn't really have a good set of infrastructure to do this and a lot of creativity was involved (including a 4.6GB git repo).
After a bit of reading, even Debian doesn't have a great set of infrastructure for bootstrapping onto a new architecture or ABI, although the Emdebian team is working on it.
This is awesome to see from both the Fedora and Debian teams. As much as Cross Linux From Scratch is a neat exercise, having the ability to bootstrap a "real" Linux distribution is very handy. Being able to base an embedded system on a well supported community distribution that can be customized through a well documented bootstrap process is an awesome thing. I'm looking forward to learning more about these methods.