One of the Xbox 360's best "features" was the requirement that all Xbox LIVE Arcade games have a demo. With the Xbox One, there's no longer a distinction between retail games and XBLA games. As such, there's no more requirement for demos for downloadable titles. To that end, some Xbox One owners may have noticed a lack of available demos on the new console — as in, there are none at all.
Responding to the issue in the comments of his Peggle 2 release post, Larry 'Major Nelson' Hryb confirmed there will be more demos for Xbox One in the future. Though he didn't get into specifics, Nelson explained, "It is (and always has been) up to game developers to do demos for their own games. They'll be more demos for Xbox One as the platform goes forward."
There's no doubt demos benefit consumers in terms of purchasing decisions, but there's an ongoing debate among the industry as to whether they help or hurt sales. I've heard equal arguments from both sides from consumers — some saying demos have convinced a consumer to buy a game they otherwise might not have, while others say demos sometimes turn them off on a game entirely. This makes the lack of demos on Xbox One particularly interesting.
Do you mind not being able to demo a game before purchasing it?