The Itanium is expected to change all that and cement Linux's position at the top-end of the corporate segment. Processor technology has come a long way. They have all been significant in powering the computers.
Processors also define the architecture and computing standards.
Since the age of 386 processors, Intel has been lugging on to 32-bit computing. 64-bit computing has been around for a while now. Several of the IT vendors tout it as a competitive edge. As companies process larger amounts of data and maintain bigger databases, 64-bit computing may become a necessity. Most of the 64-bit solutions that were available were expensive because they were proprietary and few vendors offered solutions for these.