It is apparently down to 20% now. It was a little tricky for me, so here is what I did in case it helps someone else.
I didn't have a Microsoft Passport account, so when I clicked the sign in link I had to create a new one. Once the registration was complete it took me back to the live.com search page with the same search results I entered before I signed up for the account. But it wasn't until I closed the browser tab and opened a new one with live.com that I began to see the ebay links at the top under the sponsored links.
Also, as mentioned above, only certain key words will show the ebay 20% under the sponsored links. But in case it wasn't clear, once you click through on the ebay link, you can do a new search in ebay and retain the 20% promotion. For example, if you enter "arcade" at live.com you will not see the ebay 20% link under the sponsored links at the top of the page. But if you enter "dual core computer" you will see it. Click through to ebay, and then enter "arcade" in the ebay search box. The Microsoft Cashback 20% logo will remain at the top of the screen.