Contributors/Projects/Removal of the 2006 wikitext editor should be on the deployment train for this week. It looks like @Arkanosis has a replacement script ready – which is excellent news – but @Michael Schönitzer (WMDE) and the rest of the WMDE team might want to take a look at it in advance. The change will have reached most of the non-Wikipedia projects just before this meeting starts, and this discussion indicates that a few gadgets/user scripts might need to be updated.
I've already pinged @THE IT at de.wikisource.org about this, as he's the only person at that wiki who can install gadgets. @Mpaa, @Hesperian, @Zhaladshar: The English Wikisource has no interface administrators, which means that you cannot fix scripts or install gadgets. I think you will want to change that ASAP.