Update: I was a bit let down that you just show the HN page in an iframe, nd dont actually restyle the comments in a user friendly way like in a side bar for the site (which i think would be brilliant)
The thing is, I wanted to give the user complete HN commenting functionality, and have the comments look like regular HN comments too. So I figured that sourcing the actual comments page would be the best, since you get to use it just like you would if you visited HN directly.
Shameless plug: is is my last bookmarklet for HN: http://christopherdebeer.github.com/hnCommentWatcher/
Update: I was a bit let down that you just show the HN page in an iframe, nd dont actually restyle the comments in a user friendly way like in a side bar for the site (which i think would be brilliant)