Well, I have to say, off the bat, the LiveWriter feels a lot more Microsoft-y. It's got the whole Vista/Office 2007 theme/feel to it: spacious and legible. I like it so far.
It does look like LiveWriter mimics in it's windows what the post will end up looking like (I did notice that after having connected to my blog it was downloading a few files).
It may not have a built-in youtube video file module, but it does have the ability to import plugins. A quick glance at the plugins page revealed a plugin that would allow me to add a video from youtube as well as other flashbased video providers. A definite benefit (without having to pay for it).
Though, i do like the feature from BlogJet that allows me to retrieve a previous post and edit it, pretty much on the fly. That's a nice feature to have but i'm not sure it's 60 buckaroos nice.
Edit: spoke too soon, I just found that same feature on LiveWriter, it's under File->Open Posts which pretty much rocks...
I'm gonna have to do a comparison chart/table thingy. I wonder if either one of these programs has a tool to do a quick table.
Update: I'm really digging on Windows LiveWriter.