When measuring the value of the feature, you have to ask if the feature would have been added if Michael Arrington wasn't an investor in Seesmic.

On a blog with the number of comments as TechCrunch posts have, video-comments aren't useful, quite on the contrary.

You can skim fast through text, perceiving value in some comments are reading those more carefully. With video-comments you just can't do that -- are you going to waste minutes and minutes just to 'see' the comments of a post you read in less then a minute?