User blog comment:Sarah Manley/New Editor Scheduled for Sitewide Release/@comment-1997905-20110831134812/@comment-126761-20110831142611

It's a new layout for source mode, but it's still pretty light on JavaScript (if you have visual mode turned off on your preferences, it still doesn't load visual mode code). Regardless, we are working on speed improvements across the board for both modes and are releasing tweaks every week.