It was possible to use CodeMirror's Vim mode in IPython Notebook, but in v2.x it's not possible. CodeMirror's vim.js located in "...\IPython\html\static\components\codemirror" maps Ctrl+C to Esc, but Esc is taken by IPython Notebook.
Is there any workaround in v2.x?
There is now a plugin for enabling codemirror vim mode with extra features:
https://github.com/ivanov/ipython-vimception
I've been using it since I saw the SciPy video. It has some little problems, but it works.