I would expect eBay to want to move sites they purchase to Java, since that is now their platform. (They used to use Windows DLLs in C++.) It's interesting to note that eBay is nearly the only large site that has gotten Java to work for high volumes. The problem is exactly what you describe in your last paragraph -- not so much a Java issue as one of finding talented people.
Comment on Re: Report: Migrating from perl to Java