I'd see game and software sales going down a bit - many folks like the "try before you buy" approach.
That's an often used argument (or allow me to call it "excuse"). I don't think that it is really valid.
Back in the old days before the internet, when I was 10 or 11, every boy in my school (including me) was a pirate. Everybody had every game, especially the ones that were on the "index" (i.e. illegal because of alleged damaging effects to minors). We had them all, we played them all, and none of us ever paid a single cent or intended to do so, ever. My only excuse is that I was a stupid child/teen, and luckily for me there is something like the statue of limitation, which has put me at safety regarding civil action about 15 years ago.
Either way, while I'm only using free software or am paying for the software that I use ever since I started working, I know people who went to school with me, some of them even having families (in some cases, that's truly surprising), and they
still pirate software (and movies, and songs). None of them even seems to think that they're doing anything wrong, and of course none of them intends to ever pay a cent for what they stole.
It is thus my firm belief that in general people who pirate (say, 99% of them) your stuff
don't do so for trying and buying later. They pirate for no other reason than because it doesn't cost them money.
Having said that, I could imagine that if there was somewhat less greed among software/music/movie companies and prices were a bit more reasonable, people would pirate less, with or without copy protection. When I was a teen, a typical CD or a program would cost a fortune, of which maybe 2-3% was due to attribution to the artist and material cost, another 5% was for logistics, and the rest was
greed.
This hasn't changed much. If you were to buy some software like Office or Photoshop, it costs you somewhere between 500 and 2000 Euros, for no justifiable reason. If a program like Photoshop was sold for 50 Euros, I would immediately buy a copy for at home. As it is, I'm using OpenOffice and Gimp instead, which isn't quite the same, and in particularly OO makes me shout and hit the monitor with my keyboard regularly, but it doesn't have the same smell of greed.