It's already really useful. You can create local apps with home-screen icons on it. You can install whatever packages you want (download and run StaSh inside Pythonista to get a command line with pip). You can even use git with it, again through StaSh. For me it's a first-class Python development environment that I can use when away from my main computer.

The only shortcoming today is that you can't get code into it except by grabbing it from a git repo or pasting it in from the clipboard. Today's policy change should directly address that limitation.

There are scripts you can put into Pythonista for pulling files in from Dropbox and a Gist, etc, but if you are working on a multi-file, multi-module app then syncing file by file is just way too painful. The way I do it is to run an FTP server app on the phone/iPad, connect in from my Mac and manually copy the whole directory tree. You can also export and email a zip of a directory. Snapshotting like that is survivable, but proper built-in sync or Git support is the holy grail.

You can already do quasi-pip installs on it., provided you're dealing with pure Python modules.

(I do that by syncing files from my Dropbox via the API, but there are other ways)