There have been more recent reports of Google showing longer descriptions (aka snippets) in the search results. We have reports from ThatsSEO.com, Holistic Search and SEMVironment.com with examples and screen captures. I was able to reproduce it for a search on fill empty cells with specific value openoffice.
A typical search shows a two line description or snippet:
But with the query above, you can get a three line description or snippet:
Or four line description or snippet:
Now, it seems like the longer your search query, the longer the snippet might get. But I have not fully tested this theory.