Back in the June 2006 issue of Queue, Michi Henning wrote a very good condensed history of CORBA and discussed how some of its technical limitations contributed to its downfall. While those limitations certainly aided CORBA's demise, there is a very widespread notion that the ultimate cause was the ascendance of Web Services, a notion that is compounded with the further belief that Web Services' dominance of the distributed computing landscape is indicative of its technical superiority to the systems that preceded it, such as CORBA and DCOM.
Having worked in distributed systems for a number of years—indeed far enough back in time that building a distributed system meant actually packing bits into UDP packets with lovingly hand-crafted C code—I think this assumption is unwarranted.