Microsoft needs Google, Google doesn't need Microsoft.
That's the gist of it.
Windows, Windows Phone, Windows RT, are completely useless without Google.com, and Youtube.com and Gmail support.
People don't rely on things like Bing and MSN Video, they rely on Google.
Google on the other hand doesn't need Microsoft. Google has massive mobile penetration
(almost 80% of all phones sold worldwide are now running Android, iOS and WP are a rounding error to Google)
Using those "Scroogled" and anti-Google videos was the worst thing Microsoft could have done.
Not to mention they published that stuff on Youtube...a Google site...how messed up can you get!
Are you getting Scroogled? (via bing)
Google taught Microsoft a valuable lesson, they own the mobile space and they can bring Microsoft on their knees with the switch of a button if they start a slander campaign.