Question about the future of PSN

I was wondering something today. When the PS4 comes out, has sony stated whether or not the PS1 (and possibly PS2) games that you download off PSN will transfer when the next system comes out? I was just thinking it would suck to spend all this money buying classic games to have on my PS3, only to not be able to keep them, or be forced to pay for them all over again, when the new system comes out. Has there been any word on this that i may have missed or what?

I would assume that you could use your same PSN account on the PS4. Nothing has been official, and it's nothing to worry about since the PS4 won't come out for about 3 years.