IBM is quite an pioneer in this race, and it invested big bucks in this future possibility. As Sam Palmisano said "an enterprise whose business processes—integrated end-to-end across the company and with key partners, suppliers and customers—can respond with speed to any customer demand, market opportunity or external threat."
On Demand Platform changes the way you design and implement your systems. It is started as traditional ASP model and gained lot of mileage from the hosting model and eventually got exposed as Enterprise business model because of web services/REST/XML/Utility computing and similar technologies.
Recently we are seeing a real "Check-in/Check-out On Demand Enterprise", across different aspects. From Utility Grid computing to Enterprise E-Commerce. Some of the examples are
- Enterprise services [1+]; are opening themselves to On-Demand E-Commerce.
- Sun's Grid's availability for global computing; A real Kicker to the Grid world. Data center will be available to the customers, pay per use. $1/hr of CPU usage. What Sun gets out of these is; primarily they can make Customers to use their products and possible venture into different verticals, So that's On-Demand Computing.
- Amazon's Message Queue Platform; This is a cool one, Amazon will open up its SQS(Simple Queue Service), as a add-on to its already existing web services infrastructure. Don't forget this again comes with certain usage boundaries. This makes Amazon as one of the few players moving to On-Demand Middleware.
From the technology front, IBM announcing SOMA, extension to current SOA, that will help enterprises to convert their model to On-Demand business.