It appears Google made a slight change in how they display the "cache" and "similar pages" link within the search results listings.
Yesterday, the link appeared on the same line as the URL, as shown here:
Today, the link appears on the line under the URL, as shown here:
Was this change intentional? It seems like everyone is seeing this on the main Google.com results.
Forum discussion at DigitalPoint Forums.
Update: This is no longer happening, I assume some Googler accidently put a break in there and it got pushed to the main results. It is now back to normal.