Google has made several small algorithm changes that may minimize the impact of user campaigns to make a specific site rank well for a meaningless or biased query.
According to Google's Matt Cutts, writing in Google's Webmaster Central blog:
People have asked about how we feel about Googlebombs, and we have talked about them in the past. Because these pranks are normally for phrases that are well off the beaten path, they haven't been a very high priority for us. But over time, we've seen more people assume that they are Google's opinion, or that Google has hand-coded the results for these Googlebombed queries. That's not true, and it seemed like it was worth trying to correct that misperception. So a few of us who work here got together and came up with an algorithm that minimizes the impact of many Googlebombs.
The next natural question to ask is "Why doesn't Google just edit these search results by hand?" To answer that, you need to know a little bit about how Google works. When we're faced with a bad search result or a relevance problem, our first instinct is to look for an automatic way to solve the problem instead of trying to fix a particular search by hand. Algorithms are great because they scale well: computers can process lots of data very fast, and robust algorithms often work well in many different languages. That's what we did in this case, and the extra effort to find a good algorithm helps detect Googlebombs in many different languages. We wouldn't claim that this change handles every prank that someone has attempted. But if you are aware of other potential Googlebombs, we are happy to hear feedback in our Google Web Search Help Group.
Google Blogoscoped's Philipp Lenssen has some more info, including rankings of well-known Googlebombs over time.