eBay is one very smart company. Their community based business, even though the participants do not think of itself always that way is continually growing. Culturally the two companies would seem to fit rather well too. Both understand viral marketing and how important that user community is to determining value.
Since fit is very important, this is one marriage that actually makes a lot of sense and even if it's only about eBay interest in expanding it signals a shift for them into being more than just a swap meet and financial transaction house and takes them beyond the place of just being a bourse.