Microsoft and BEA+Sun were the chief rivals in this bidding process, but eBay claims it went with IBM because of IBM's deep Java experience.
That makes me wonder: any suitably talented small team could build a large webapp the size of eBay in a handful of languages and environments. Paul Graham is fond of pointing out that he built an ecommerce system in Lisp, and that Orbitz was originally implemented in Common Lisp. Ars Digita was attempting to do similar types of things by using Tcl. With enough force, I'm sure you could build a similar kind of big site using Zope, PHP or even Korn Shell.
So, where is the large-scale trial-by-fire story for Perl?