There's a lot of optimization still to be done (including X11) but look forward to a Raspberry Pi Fedora image (spin/remix), Fedora 15 for ARM, and the Raspberry Pi device itself all being available next month.
(In or near Toronto? There are three talks related to Fedora ARM and/or the Raspberry Pi at FSOSS next week).
That bottom link is Firefox on Android, presumably ARM\Linux and Android are different due to the nature of Android. That's not to say anything about ARM\Linux running Firefox, just that I don't think that your second link is relevant.
Yes, Firefox runs, but it consumes too much memory for this device with the default Fedora build options. A Seneca student is looking at ways it can be optimized, and another is looking at alternative browsers.
These are my first two books: X Power Tools, a thorough guide to the X Window System (O'Reilly, ISBN 9780596101954) and Fedora Linux: A Complete Guide to Red Hat's Community Distro, a practical hands-on book on Fedora (O'Reilly, ISBN 9780596526825).
Fedora Linux is also available for online reading through Safari and in downloadable PDF format from oreilly.com