Yahoo!

* been in the search game for many years.
* is better than MSN but nowhere near as good as Google at determining if a link is a natural citation or not.
* has a ton of internal content and a paid inclusion program. both of which give them incentive to bias search results toward commercial results
* things like cheesy off topic reciprocal links still work great in Yahoo!

MSN Search

* new to the search game
* is bad at determining if a link is natural or artificial in nature
* due to sucking at link analysis they place too much weight on the page content
* their poor relevancy algorithms cause a heavy bias toward commercial results
* likes bursty recent links
* new sites that are generally untrusted in other systems can rank quickly in MSN Search
* things like cheesy off topic reciprocal links still work great in MSN Search

Google

* has been in the search game a long time, and saw the web graph when it is much cleaner than the current web graph
* is much better than the other engines at determining if a link is a true editorial citation or an artificial link
* looks for natural link growth over time
* heavily biases search results toward informational resources
* trusts old sites way too much
* a page on a site or subdomain of a site with significant age or link related trust can rank much better than it should, even with no external citations
* they have aggressive duplicate content filters that filter out many pages with similar content
* if a page is obviously focused on a term they may filter the document out for that term. on page variation and link anchor text variation are important. a page with a single reference or a few references of a modifier will frequently outrank pages that are heavily focused on a search phrase containing that modifier
* crawl depth determined not only by link quantity, but also link quality. Excessive low quality links may make your site less likely to be crawled deep or even included in the index.
* things like cheesy off topic reciprocal links are generally ineffective in Google when you consider the associated opportunity cost

Sponsored links

Hi,

It's quite informative post. However, MSN search would be count as a Bing.