I’m having similar issues with Jetpack in the latest version of WP (clean install of 3.5). If I try to add a new post, the WYSIWYG editor is blank and I cannot select the form. If I try to edit a previous post, then I get only the title field appear and the rest of the page is blank.
This is the only plugin I have installed, and disabling it fixes both issues. I have had intermittent issues with it, and re-installing seems to work, until I add a new post, where it then brings these issues again.
Also tried reinstalling WordPress, but no effect.
There are no errors appearing in the Chrome console either.