Is this rule official or just a suggestion? That's damn cool if it is official. So I can now "purchase" all those things that looked nice but weren't really worth the cost, use them for up to 90 days and then return them for a full refund? Wow, thanks Apple.

Thinking about it, games in particular are going to be destroyed by this. I could finish (or become bored of) most of the games on the App Store well within the 90 day time limit. Most games I've downloaded so far I'm bored of within a few hours.