Similar issue here, using Chrome Canary Version 42.0.2290.4 canary (64-bit) with Adblock Plus 1.8.10
Every Youtube page freezes for 5-10 seconds, and occasionally the "He's dead, Jim!" message pops up. The issue is resolved when ABP is disabled. This is the only extension that causes the issue (other than Youtube Center, which is disabled for the time being). It has been happening for a couple weeks, but since Youtube rolled out its permanent HTML5 support this week, I've been getting the Jim message quite a bit more frequently, despite having already been using HTML5 as the default player for several months.
As soon as a Youtube link is loaded, the entire page freezes and nothing below the bookmarks bar is clickable. The cursor is locked to whatever state it was before the freeze, such as the index finger hand if I so happened to be moused over a clickable link before the freeze occurred. Upon trying to exit the tab, it will hang for a second before closing completely.