It isn't like the old days, when Xbox Arcade required trials.
"It is (and always has been) up to game developers to do demos for their own games," says Major Nelson. "There'll be more demos for Xbox One as the platform goes forward." This may come as a relief to those who miss the good old days, when Xbox Live Arcade required developers to put trial copies out, since Bing demo searches often have very little result.
Marc Whitten said, back in September, that "not all games will have demos like Xbox Live Arcade games have had on Xbox 360," and gamers are beginning to miss the chance to try before they buy. But as Jesse Schell pointed out back in February, demos can be counterproductive, from a developer's perspective.
"You mean we spent all this money making a demo and getting it out there," said Schell, "and it cut our sales in half?" That was the conclusion he came to, when he noticed that Xbox 360 games with a demo and a trailer sold about half as many copies as those with a trailer alone.
It will be interesting to see the data again, once more demos start populating the Xbox One world.