There are a lot of different implementations out there at the moment. A common extension for XML will benefit enterprises because they'll be able to count on this API to be stable and secure, and they needn't be concerned about incompatibilities with each vendor using a proprietary parser.
Quotes about incompatibilities (2 Quotes)
As usual, most enterprise customers will probably take a very cautious approach. Most won't rush in unless they absolutely have to for performance and scalability reasons, especially if it's a deep software stack on top of the operating system. They'll be too concerned about software incompatibilities.