IMHO, The redesign of Google Reader to integrate with Google+ do not impress me.
I am agree with the review of ex-Product Manager of Google Reader. The space allocated for reading is just too small, and I personally like the light blue theme than the current grey scale page.
I failed to google any workable way to restore the old Google look and feel. However, I found the ways to enhance the Google Reader (for Firefox).
Below is the original new Google Reader look and feel:
Below is the modified look and feel:
Below are the steps:
1. Install Greasemonkey plugin
2. Install script "Google Reader - Compact Design" (this script make interface more compact thus give you more space to read)
3. Install Stylish plugin
4. Install user style "Google Reader Revert" (to get back the light blue theme)
So far this 2 scripts do not conflict with each other. Feel free to try.