Yes I’m against Video Comments, No I don’t think they will do amazing. TechCrunch’s Michael Arrington (who has invested in Seesmic) made a post about TechCrunch’s blogs now using “video comments, powered by Seesmic”. It uses a Wordpress Plugin to allow users to respond to blog posts via video.

Here’s the reason’s why I don’t think Video Comments will make a huge splash. They take too long to make… It’s a lot easier to just write a sentence than it is to make the video, convert it, upload it, and post it.
People like to scan… You can’t fast forward things. I might want to hear the whole comment from Michael, but probably not from the random guy that just said “Hey nice blog post, I really like it and I’ll be coming back again soon” ; Great I just wasted 30 seconds watching a schmuck add nothing to the conversation.
You can’t watch them at work… You have to listen to them, how are you supposed to hide that from your boss?
Spam is going to be a b*tch!… Can you imagine the amount of porn clips that are going to be posted as comments?!
Getting Rick Rolled is going to get out of hand… I can’t wait till comments start off with a guy talk then cut to the Rick Roll video.

Summary:
Video Comments are cool… right now… they won’t be once the novelty has worn off. Some blogs might use them and do well, but I think it will be very niche related, or author specific only.

I do see a use in if you are branding your person. For example, if I posted all my replies to comments on my blog as a video, my readers would get to see me more. I’d make sure I translate my comments to text, an extra step the average commenter wouldn’t do.