I haven't had a lot of time to play with it but what I see so far I like.
The updated design is minimalistic and stays true to the other design updates Google's been applying to their other products. Google Reader even seems to load a little bit faster which is a huge win in my opinion.
Some people are upset about the layout of the new sharing options and how it blatantly promotes Google+ sharing. To that I say: big deal. If you can help your own product in any way you'd do the same.
The main issue I was worried about when the re-design was announced was that the usability of Google Reader would decline. Ater using it for one day I find my speed at reading through hundreds of RSS items to have not slowed in any way.
Good job Google Reader team!