Google unveiled WebM at the Google I/O this week. WebM is open web media format featuring the now open-source VP8 video codec. The Register reports that Steve Jobs answered an email about VP8 with a link to a blog post that sees VP8 weaker than H.264.
H.264 is the video codec Apple currently embraces in Safari's HTML5 video. Given the tensions between Apple and Google it is not surprising that Apple is critical about WebM.
With WebM Google increases the momentum behind HTML5 video. I am not sure if it will matter for end users which codec wins at the end. We just want to watch video on any device.