These are suggestions designed to help you easily narrow your request to a particular topic, if your original search was ambiguous. While those words will appear in the search box, behind the scenes they are mapped to other words that editors at MSN Search believe will bring up the best sites for that topic. Moreover, the editors may have preselected what they believe to be the best sites for that particular query. That's just one example of the hard work going on at MSN Search to improve the quality of their results. A team of editors closely monitors search logs and provides human intervention where needed to improve the listings.
Misspellings are a good example.
Select this link, and you'll be shown all the different topics related to your original search. After doing a search, you'll see that the results screen has gained some new tabs at the top of the page. The feature that allowed those using Internet Explorer to save results has now been removed. I always thought this was pretty cool, but users generally didn't take advantage of it. Given this, it was dropped to make the results page less cluttered.