More and more people are noticing Google's new more results user interface, where it shows a plus box, instead of taking the user to a site command like search result.
You can likely reproduce the plus box yourself for a search on sitelinks. You will notice the page looks like this:
If you click on the blue link plus box that reads, "Show more results from googlewebmastercentral.blogspot.com" it will expand to show you five additional results:
Then it will add the option to take you to a site command search, on a new Google search results page, if you want that.
This is something Google has been doing or testing since early August of this year. This was the old way:
Forum discussion at WebmasterWorld.