Not sure if you can get that specific effect, but Cathode for Mac has lots of options:

http://www.secretgeometry.com/apps/cathode/

The author talked to the Cathode developer and even opened a feature request for iTerm2[1]. There seems to be some interest in this. Cathode is mostly about emulating old, slow hardware, this would be about the opposite (code wouldn't look too differently, though). A "movie hacker" terminal or editor for live coding would be pretty interesting. Hmm, maybe in addition to Xt/Gtk/OSX one could add an OpenGL interface to Emacs for maximum scriptability.

1: https://vimeo.com/22798433

I've just ported the theme to Emacs 24 [1] custom-theme.el and made the same realization.

[1] : https://gist.github.com/3723433

Yes, I was thinking it'd be fun to be able to switch Emacs into that mode at times. No doubt it'd drive you crazy if you used it too long though...

I think I've seen an Emacs video using the same "fake old retro" scanline look but I'm not sure how it was made. Could have been postprocessed on the whole video too.

Does anyone know how this effect was achieved?

After effects can do this easily:

For the glow: duplicate the video layer, add a fast blur effect and set it to overlay or color dodge blending mode.

For the scanlines: AFX has a scanlines/cathode effect that you can tweak to re-create that look. I can't recall off the top of my head how it's done, but I can look it up if you'd like (I've done it before, while fucking around in AFX [1]).

[1]: https://vimeo.com/41453548

I don't think OP actually wants to know how he can do that with post-processing, but in a real Emacs session.