[I've had this saved as a draft for about a week, because it wasn't as complete as i'd like. But i'm gonna go ahead and publish it and just make updates as needed.]

Some reference material as i begin to dig into updating LCD for this new-fangled Firefox 1.5 thingy:

The ever-vigilant Jesse Ruderman’s 1.5 changelog is a great starting point:
• A MozillaZine Forums post about the new chrome manifest file system [new, easier way to set up theme development installations (no more install.rdf hokey-pokey)]
• Mozilla Bug 295265 – chrome registry overrides [possible way of setting up development installations of themes]

List of theme changes from 1.0 to 1.5 compiled by ehume and the ensuing discussion at the MozillaZine Themes Forum. Seems fairly comprehensive. Unfortunately, changes were posted to the thread upon discovery, but no master list was kept as far as i can tell—and i haven’t yet am not about to read through all 23 pages of that sucker. That type of info would be much better off (not to mention more accessible) as a KnowledgeBase article.
• Options Window (Pref V)