I can zoom through articles pressing the left/right arrows with no perceptible latency.
Google Reader is slow and not very efficient when you have a lot of subscriptions but unread articles is not its problem. IMO Google Reader's home page can be improved more than just displaying new articles. It could display most read, most recommended articles etc ... from your feeds.
Oh, wait.
FTFY.
Following your logic we should have TFT-displays with bendable corners, so we can make "real" bookmarks...
You are not.
As they indicate in the about page Google intends the target to be people who flip through magazines and when they see a title that interests them or a picture of someone they recognize they then read the article.
Whether that market exists or will be the actual market (if any) of this "product" remains to be seen.
In my opinion, I could see something like this working if it was presenting me with printed content (say the actual print newspaper or magazine, which in some instances you can get in pdf viewer format that is similar to this). But for web content, the existing method is better. The new format is actually harder to read/scan (and I'm using a 22inch display). So I expand the many articles to one per page, and use the arrow navigation to go article to article. The result is more time spent trying to catch up on news, and more clicks since I have to bypass the articles I have no interest in reading. My choice would be to go elsewhere if this was all Google News provided.