Ok, I'm quite irked by this story, and I got modded troll a bunch of times by trying to point out that Google's experiment doesn't really support their accusation. I know some people will immediately label me a shill or apologist just for having a different opinion. What's stupid is I use Google search, and never Bing.
Anyways, the following is my understanding and some opinion. The secret knowledge of the search engine is the association of a search term and a result (usually a url). So to say that Bing is copying (I think 'cheating' might have the what was used, but copying is a lot of people's interpretation), implies they are acquiring Google's association data; conversely if the Bing search comes to the same result coincidentally, then they can't be 'cheating'. It wouldn't be that surprising if two search engines return same results for certain words. However, Google did their sting with fake terms... so obviously Bing is copying right?
So let's talk about their sting. They created (100?) honeypot search terms where a fake word would return a real link 'sss4yxyxy -> returns www.myresult.com'. Then they had 20 employees using IE and Bing toolbar w/ Google search and kept using these fake terms, then clicking the resulting link. Some time later, some of these fake terms return the same results on Bing.
A few things: Google employees opted into tracking w/ the Bing toolbar. (This is somewhat beside the point anyways, since Google isn't exactly in a position to point the finger about tracking.) Note that my understanding is that few of the (100?) honeypot terms actually worked on Bing.
The explanation from MS is that the Google employees gamed their user tracking mechanism to produce a result which makes it appear as if Bing is 'copying' Google. Basically they tracked the user search term, then the link they clicked through, and used this as part of the data for Bing. Google successfully gamed this because those terms are fake, and therefore the only data about them came from the sting.
So my opinion is that this isn't copying. If 100 of 100 honeypots showed up on Bing then that would support their accusation better. If their 20 employees only used Google normally from IE, without going through the toolbar, then that would strengthen the case. Without these, I have a hard time understanding how even the people at Google have rationalized their own accusation. Now maybe MS is lying and I'm a chump, but at least I'm taking the time to consider the evidence as presented.