Ebay is an auction site. PayPal is one of the payment methods for sending payment. Bitcoin is another.
It is happening.
[Click "See Full Description"] :
"For this auction I am willing to take bitcoin or paypal."
Bio: "Oh, by the way, I accept Bitcoins."
In addition to seeing Bitcoin appear in more listings and profiles, I expect to see ClearCoin start appearing as an escrow method. Combining bitcoins for payment and ClearCoin for escrow is a combination that has so going for it. There's almost no other alternative for affordable escrow for $100 or less purchases. Add in the #bitcoin-otc gpg Web of Trust and there no reason these tools can't be used by a wider user base.