Wasn't sure whether to post here or Alternatives.

How have the Debian on N900 WIPs been going?
Are any of them still being worked on? How far did they get?
Any of them get to a state where all the hardware works?

There's Easy Debian which runs as chroot under Maemo[1]. The last major development with that was that sulu created and shared an image of Jessie which include a hacked glibc that allows it to run with Maemo's old kernel[2].

If you're looking to boot into Debian with a recent kernel then various people, including myself have provided instructions for setting this up. If you're not familiar with my project then check out the DebiaN900 thread I've linked to in my signature. My project is on hold at the moment due to other commitments but I'm hoping I can resume in a few months time. The hardware doesn't all work yet, what works is very much dependent on which kernel is used[3]. There are small bunch of developers that continually work on mainlining kernel patches. Pali's kernel[4] also includes patches that have not been mainlined. As my project hasn't been updated for a while, the default kernel that is checked out is a little old now but that can be changed easily by editing the branch name in the conf file if you want to try the latest. For the latest kernel discussions, check out the linux-omap mailing list[5].

[1] http://talk.maemo.org/showthread.php?t=34550
[2] http://talk.maemo.org/showpost.php?p...postcount=3138
[3] http://elinux.org/N900
[4] https://github.com/pali/linux-n900/
[5] http://www.spinics.net/lists/linux-omap/