It appears that Google Base is using Ebay Store Info when they do not have relevant product data for their 'base' product to use. I searched using a long tail keyword and only got 1 result and it was Ebay.
So, I'm wondering which will Google display first in the Base SERP's. Ebay or Base (provided theirs data). This goes without saying that the Base feed needs to be optimized, but just how much more, if any, is the Ebay result valued because of Ebays link love?