The thing about this lens and video is, is that the focus ring is REALLY tiny, flimsy and loose. So focusing will be really hard to do. Also the focus ring is all the way at the front and it's a front-focusing element, which is kinda sucky for video. Now, apart from all the difficulties to use it for video, it's an amazing lens for the money.
Though, if you just wanted it for video, you should've gone for an SMC-Takumar 50mm f/1.4. That would've been better for the money: faster, better IQ and all metal build with a nice focus ring.
Still: the Canon 50mm is also a GREAT lens for the price!