The App Store's lack of a trial process or refund policy has been one of the few downfalls of an otherwise successful venture. Though some 3rd party developers offer refunds under special circumstances, it's not a bet you'd ever be willing to make.
But if you recall last month, there were reports going around that Apple was making a change to its App Store policy. Word on the street was that the Cupertino company was going to implement a 7-day app return policy for the folks in Taiwan to comply with a government mandate...