Your comments

(Oh yes - and the fact that hg is pure python can't help either )
You didn't see my comment for mercurial right below yours? Truthfully though, I can't see how the GPL licensing of mercurial makes it possible.

In any case, I think Alexander knows we're keen ;)
Indeed - implementing a full version control client would *be* a lot of work. (merging, in particular)

I've gotten a long way with my text files by using Textastic to sync changes to a server running HgAutosync -, which does its best to do smart merges without bothering the user. You could probably get the same result by using dropbox, actually.

That feels like a nice way of doing things... Textastic still falls a little short of the mark, though, since its file sync pane doesn't seem to gracefully "sync" with the server. I can upload or download files, but it's up to me to remember which ones i've changed and guess which ones have changed on the server.

Maybe what we need here is an rsync-like upload/download system that syncs latest changes (and warns of clashes?), and then let the server running autosync/flashbake/dropbox handle the details of storing updates? That would be pretty neat, and would fix my versioning needs at least. Right now, though, I have to keep a piece of paper next to the ipad and write down what fiels I changed, which isn't optimal ;)
Ah, and in fact both github - and bitbucket - - support SVN access to their repositories. So if the Git.framework thing didn't work, might be an avenue to just support SVN.
Ah, the trials of iOs development.

It's not an Objective-C solution, but perhaps some kind of Webkit integration and the MPL'd Ace editor (written in Javascript) would help?

Although I'll warrant that's not what you were hoping for.
...and yes, the prepondence of GPL licenses in SCM is very annoying, is it not? Fossil - - is BSD, and the as-yet-untried Veracity is APL - ... JGit is a BSD Git implementation, but it's Java. Grrrr.
One can access any version control system using autoversioning (e.g. flashbake for git, or, or WsgiDAV.

The major obstacle, AFAICS, is that you'd ideally want to access your precious source control repository using a secure protocol like SFTP or WebDAV+https... leastways, when i mentioned to the sysadmin at the office I wanted FTP access so I could edit files using Textastic, he nearly broke the ipad over my head.