Justin.Tv, Leo Laporte, Revision3, Dvorak, Adam Curry, Jason Calacanis (ThisWeekIn.com), are blazing the trail.
I'm watching more videos, than reading blogs lately. How about you?
Video can be very informative when it is instructional, and of course when it's entertaining.
Video is dull as dish water when it's talking heads, unless the talking heads are exceptionally interesting, informative, or entertaining. Talk show host s earn their crust. It's not as easy as it looks.
Producing good video is just as hard as producing good text. But you can scan less than stellar text to find the good stuff. It's hard to scan video for the good stuff.
So, on the whole, text beats video unless you _really_ know what you are doing and are critiquing hard.
Works better for categories like eSports, Cooking, How To.
This is true for Ipad and PC. I can't speak to the other platforms.
If you want to succeed with a video blog, then you need to script it, deliver it with punch, include strong supporting material (not stock footage). The more it is like a good TV ad (most are plain awful) or a good MTV clip the more likely it will get watched. Oh, and forget long trailers, they are a turn-off.
Video is a skill in itself. Put your average blogger in front of a camera and it will more than likely turn out badly because most people aren't skilled orators with the ability to manipulate their own body language.