I hate the new 15-minute period as much as the next person, but 7 days is ridiculous for software purchases on the scale of mobile apps. Many of them could be completed and boring in 7 days. It protects the consumer but destroys the publisher.
Even the 1 day period felt long to me, but there was a few times I was glad it was that long... Apps that claim to work but don't come to mind. Sometimes it takes hours to get it to download properly. I have actually refunded an app that I couldn't download within the 24 hour period, despite most 500mb+ apps taking less than 10 minutes to download.
So I can defend 1 day, but not 7. That's not a trial period, it's the entire life of the app.
There are arguments that apps that small shouldn't be for sale in the first place. But people aren't forced to buy them. If they don't think they are worth the money, they shouldn't buy them.
Although frankly speaking, 7 days is too long for apps, the law is originally made to restrict post sells and other physicals goods sales that buyer have no idea the quality is before they receive the goods, I think its quite reasonable.
The Android market already lets you customize your trial duration, though in a second-best manner—you upload both a demo and a regular version of the app. Of course, there are a bunch of problems, like trying to migrate data.
But they've applied it to mobile apps, which makes it ridiculous.
BUT, I also realize that the app stores can't create separate policies for every jurisdiction on the planet -- there are too many and it is too difficult. So Google's "solution" is probably the best way to deal with a bad situation.