I think the changes look good. I would suggest a couple more changes:
1) Somehow distinguish the site name and random quote header part from the posts section. (Maybe make this section gray instead of alternating posts?)
2) Add some kind of border to the sides, or change the bg color of the posts - something which makes it easy to keep my eyes more focused on the main content.
Something you may also want to consider is a more definitive post title. Maybe make the post title with a gray bg (if you're going with the gray/white theme) and use that as a demarcation between posts. Also, making the post title bold. (I noticed you're just using an anchor tag for your post titles. Why not use an h2 tag?
I think what you have is coming along quite nicely. Simple, light, and easy on the eyes. Are you planning on making this into a downloadable theme? I wouldn't mind playing with this around a bit on my own site. I think it has a lot of potential for pliability.
Finally, consider using table-less CSS for future designs. As it is, there's not much to your code, which is great, but table-less design may make your site easier on the mobile-browser crowd (myself included) over the long haul, as well as on the folks using accessibility technologies (again, myself included.) Besides, it's good for SEO :-D