Moving Satchmo to the latest version of Django's trunk after the newforms-admin merge was fairly easy.
First, I updated Django, and Satchmo itself. I thought that it might have been that easy. More or less, it is.
I ran into one gotcha. Satchmo makes you copy a bunch of files into the project that will install the various Satchmo apps. I may not have installed Satchmo properly, but my url.py was the one that Satchmo had previously spit out. This is no big deal since Satchmo was the only app I ever intend to host on this particular shop, but I did have to go in and add the new import for the admin, the autodiscover line, and update the urlpattern for the admin site to reflect how Satchmo's new urls file is configured.
Once that was done, the shop seemed to be fully operational again.
The next step is to finish setting everything up, and actually make the store go live.