It's less focused on the data analysis side and more focused on collaborative coding for interview environments. You get a full IPython shell with most of the niceties (syntax highlighting, exception captures, etc).
I know it's not a big deal to get data another way, but it'd allow for the following of a tutorial like Learn Python the Hard Way totally in-browser.
I might not therefore be the target market.
Crying shame.
That being said, I've been working on making it easier for pure python importing, and one fun thing is that you can actually mount an HTTP/CORS-accessible endpoint as a file system and import that. I have done this with a pastebin; I turned on CORS, mounted it inside the NaCl kernel, and executed pastes.
Being able to do this interactively is going to be a huge win.