A. Labled Section Transclution (at least en and he)
http://bugzilla.wikimedia.org/show_bug.cgi?id=5881
http://www.mediawiki.org/wiki/Extension:Labeled_Section_Transclusion (stable)

B. DjVu support for ProofreadPage (general)
http://bugzilla.wikimedia.org/show_bug.cgi?id=7957

C. DynamicPageList (at least en and de)
http://bugzilla.wikimedia.org/show_bug.cgi?id=8563
http://www.mediawiki.org/wiki/Extension:DynamicPageList (stable)

D. WikiTeX (general for sheet music)
http://bugzilla.wikimedia.org/show_bug.cgi?id=1792

E. Also Stable Versions, but that should be a priority
outside of Wikisource.  If Stable Version never happens,
we might want revive Protect Section as substitute.
http://www.mediawiki.org/wiki/Extension:FlaggedRevs

Of these five features, (B) has been debugged and fully
implemented on all Wikisource wikis thanks to the fantastic
efforts of ThomasV. (E) has indeed become a priority outside
Wikisource, and is slated to become the next major software
change for Mediawiki on **all** projects (see the Extension
Page, its talk, and the Mediawiki Roadmap:
http://www.mediawiki.org/wiki/MediaWiki_roadmap

In my opinion, once (E) is implemented, and especially in
conjunction with Proofread Page (already active), the
valid concerns about the reliability of texts in our wiki
environment may be put to rest, and Protect
 Section will
no longer be necessary.

That leaves us with just three left. Two of them, namely
(A) Labeled Section Transclusion and (D) WikiTeX for sheet
music, both of which seem to be very basic, flexible tools
that should be enabled for all Wikisource languages.

ThomasV, might you be able to use your SVN access to help
with some of these?

As for (C), DynamicPageList, can someone remind me when
this was requested for Wikisource and why? (I'm not saying
it's not useful, I just don't remember.)

Dovi