Today Google has claimed that Bing is now using Google's Search Results in its own search engine. The claim - and that it is denied by Microsoft - was asserted on the Google Webmaster blog. Bing have posted a reply.
The evidence produced by Google is for a search for [torsorophy], which is a misspelling of a surgical term ("tarsorrhaphy"). But this resulted in a very narrow result set (just 2 pages or results are returned) which Bing returned (although only 1 of the 2 URL's matched Google's - so hardly concrete evidence).
Incidently, a single or two word phrase that returns just 2 results is known as a Googlewhack and are very rare.
My reading of this is that Google is accusing Bing of using it's toolbar to help it crawl the web and develop search suggestions. The argument it is putting forward is that it discovers these pages through it's web crawling and indexing systems "organically" whereas Bing is just copying them from the results gathered by the IE 8 toolbar.
It's not stating that Bing is just using Google's results or result order in it's searches. Interesting to see how this pans out.