Cloud adopters face serious risk in the next two years because of the strong possibility that their provider will be acquired or forced out of business, according to Gartner. The research firm is predicting a major consolidation in cloud services and estimates that about 25 percent of the top 100 IT service providers in the infrastructure space won't be around by 2015. "One in four vendors will be gone for whatever reason -- acquisition, bankruptcy," said William Maurer, a Gartner analyst. Most of the time, the changes will come through acquisition.