Slides are online, and the talk was videoed, so I imagine that the video will go online one day too.
So, once you’ve Debian bootstrapped the NSLU2 slug, there isn’t any way I can see to get new kernel modules for DebianSlug. However, you can download the unslung kernel modules, unpack them and use the kernel module from that. Unpacking looks like this:
wget "http://www.student-zw.fh-kl.de/~pasc0010/debianslug/kernel-modules/ kernel-2.6.16_preempt/kernel-module-raid1_2.6.16-rc4-git9-r0.0_ixp4xxle.ipk" ar -x kernel-module-raid1_2.6.16-rc4-git9-r0.0_ixp4xxle.ipk tar xvzf data.tar.gz cd lib/modules/2.6.16/kernel/drivers/md/
And there you go.