Sony doesnt have great-selling titles but they have a lot of middling selling titles and Im sure they will make sure to have some of these at launch. Assuming that the ps4 launches at the end of 2013 - I can see them having a Infamous 3, UC4 and Killzone 4 title at launch. If they manage to get any 3rd party exclusives timed or otherwise (japanese) to launch along with it, then it could be a very attractive buy. Especially as it will likely not be priced too high AND will come with a blue-ray like the ps3.
Edit: And I agree with some of the other posts - if they initiate ps+ at launch for the console, they could have a very attractive console for those budget-conscious gamers who want games but wouldnt want to pay the hundreds of dollars to get them.
<a href="https://psnprofiles.com/fauzman"><img src="https://card.psnprofiles.com/2/fauzman.png" border="0"></a>
