I personally do not see them anymore either - although I am not sure if it was removed during or before the new design launched a couple weeks ago. We do know that Google dropped realtime, wonderwheel and image sizes after the new design, although some were not removed because of the new design.
Here is a picture of the similar link as it was during the old design.
Now, to access them, you need to use the instant previews feature and at the bottom of the preview, you will see a link to "similar."
Google still has the pages similar to feature on select queries but not the similar link on each result.
If you really miss it, you can search for similar pages on Google as related:www.seroundtable.com - the thing is, the query doesn't work as well as it once did.
Forum discussion at Google Web Search Help.