That sounds quite easy, then.
One of my worries was the kernel packaging, because I build the package by hand, just putting together the binaries after a make, and thought we couldn't do a cssu until this were sorted (because the non-existent autobuilder). Of course, I'd prefer building the package with dpkg-buildpackage from sources, to have less chances of making a mistake, but I do not understand well how a multi-package build works (dpkg documentation is awful, isn't it?), and need for someone to explain it to me.

Anyway, I'd start by putting the following packages into CSSU (testing for now):
bluez-utils_3.28-0osso7_armel.deb
dbus_1.0.2-0osso16_armel.deb
dbus-1-utils_1.0.2-0osso16_armel.deb
libdbus-1-3_1.0.2-0osso16_armel.deb
mini-rc_0.2.11-3_all.deb
gconf2_2.16.0-1osso15_armel.deb
libgconf2-6_2.16.0-1osso15_armel.deb
This one to be pulled only by rx-44 and rx-48 (N810), as it's not needed in N800
gpsdriver-guard_1.0.0-4_all.deb
This one not to be pulled, but available as an update
bluez-utils-test_3.28-0osso7_armel.deb

Those packages are unlikely to change anymore (at least untill I put in new features), and many of them are system packages and that's forcing DT users to install osso-software-version-unlocked. Also, it's very unlikely that those packages cause any problem to current CSSU users.

What's left out are the kernel/modules packages for now.
The current kernel package needs a small change. Actually it backups the old kernel to restore it if uninstalled, but in a SSU it needs to be a simple kernel package. I'll maintain the modules backup though, so they are restored if anyone installs a kernel not in the DT series.
The modules available in extras-devel are a problem, fuse-modules from PC-Connectivity-manager in particular because they are version locked, so we'll have to ask for/make ourselves a new PC-Connectivity-manager build with modules version unlocked, and then provide the DT version of those modules as update.

P.S.: This could be a good moment to pull in those hildon UI packages that have been appearing in the cssu thread lately.