Perhaps "killer" was too strong a word, but it will certainly shrink the Edge's appeal outside of the small niche market who need the annotation capabilities if it comes out. And that niche is significantly smaller than academia in general. People who are looking for ereader capabilities and netbook capabilities in a single device are going to have an option that has much better performance as a netbook and only slightly weaker performance as an ereader, at a price $50 less.

The active digitizer difference is a notable one, but for those who are just writing on the margins of a document that's probably not a big deal as the back of your hand won't be touching the screen as you write. As for note-taking, I'm still not convinced the Edge is better for this task than a notebook and a pen/pencil, considering the smaller page size, lower resolution, and that you have to pay $30 to get a pen-sized stylus and who knows how long it will last before the tip wears out. I for one am still going to take notes with paper notebooks or a laptop with LyX if legibility is important.