while game makers like Microsoft, Harmonix and Sony are preparing to offer games. Despite all this enthusiasm, Facebook CEO Mark Zuckerberg -- who pushed Facebook to buy Oculus last year -- has begun lowering expectations for how quick the uptake will be for these devices. "This is going to grow slowly," he warned in September. "If you think about the arrival of computers or smart phones, the first units shipped did not ship tens of millions in their first year. But they proved an idea and made it real." For now, HTC said it plans to offer 7,000 more prototypes of its device to developers ahead of next year's launch