There are two criteria you can use to judge. One is new last-gen exclusive game releases and new game releases. Last-gen has Assassin's Creed Rogue as an exclusive. And pre-Christmas virtually all new games are coming out on PS3/360. e.g. Call of Duty, Dragon Age, FIFA etc. However in 2015 I think exclusives will non-existent and it might be the last year of cross-gen games besides the mega franchises.
The other is sales of console units and games. As the console price of 360 and PS3 get cheaper they will continue to sell to young gamers and should have a long tail. But sales figures (UK & USA) for new cross-gen game releases show that PS4 versions are always outselling last-gen versions. Which means the hardcore have move to new-gen.
So yes 360 and PS3 have got a lot of sales to come, but no we won't see anything new on them. Next-gen exclusives will start pouring in next year. Therefore last-gen ends in 2015!