Seems a bit of a waste of time really releasing a cripped version.
Will be interesting to hear the dev's views on whether it's had any impact on sales or not.
Looking around the net I would bet that's it's had a hugely positive effect on sales. Most of the main news sites have run with the story and the devs website has been down most of the time since due to being overloaded. Free publicity and all that.
It might not have been their original aim, but it might turn out to be a stroke of marketing genius.
FWIW I can think of a few positives of releasing a pirated version of your own game too although it's probably not worth the effort for most of us