Apparently, you can get the old interface back with a little hack.
You can complain here: http://www.google.com/quality_form
For uniformity, let’s complain using the same options. Select the option from my screenshot below.
The new left navigation is horrible. Don’t get me wrong, I like the functionality the left rail exposes. I like being able to easily filter my results by content type, date, etc… but I don’t want those features in a left rail.
Simply put, the left rail undermines what originally made Google great: simplicity. Google has always been visually simple, allowing me to easily scan search results. The new left rail is just a distraction. It takes some of the most valuable screen real estate and fills it with something that is not always needed.
The most important information on the page is my search results, not the sorting, filtering, or ordering therein. When I use Google, I want to access search results 100% of the time. The algorithm is so good, most of the time I don’t even need to refine my results because the answer is right there. I want to filter my results significantly less often.
The search filtering might be better suited to a right rail: there when I need it, ignorable when I don’t.
The new left rail also removes an important visual cue from the page: the browser left edge. My brain naturally tracks to the left edge of the browser window, much like reading a book. Now, instead of shiny clean search results, I get the left bar. While there is still a line for visually tracking the edge of search results, its soft coloring doesn’t give you a strong visual cue for the left edge of the content area; the contrast between the browser edge and the page is still a stronger cue. I end up scanning to the left edge of the browser, bringing my attention back to this evil left rail.
I understand that you want to advance your search engine, exposing more features to your customers. I’m all for it. However, those changes should not come at the expense of a tried and true product. You should let long-term customers retain their current configuration, if they desire. Give users the new look by default, but let account holders turn it off.
Remember “New Coke”? Instead of replacing their tried and true product, they could have released it alongside their flagship product. Don’t repeat the mistakes of your predecessors!
Please don’t make me hack it away.