Maybe there is a PS4 version coming and will be announced in E3. As for Drive Club I thought that is a arcade racer and not a sim. I also have a gut feeling Sony will announce instant game collection for PS4 at E3 and Drive Club will be the first game for the service.
Of course they're making a PS4 version but they won't talk about it this year.
Their strategy is clear, the game is not bound to PS3 but it's being built as scalable.
This year they sell GT6 to PS3 users and Drive Club to PS4 early adopters.
Next year they announce GT6 PS4 edition with full features, all DLCs included and so on.
Annoucing GT on PS4 this year would ruin the plan, so I wouldn't expect a PS4 GT announcement anytime soon, except for vague hints like 'yeah at some point of course there will be a GT game on PS4'.