More info here.
It's a confusing article though, it reckons there'll be five classic cars from the eighties and nineties, the mentions the first
batch including the '88 Lotus 100T, FW07, W-J F12, and "some Ferrari's", then
six classic Williams' and Ferrari's from the nineties, the FW14B, FW18, F399. That's not 6, and makes no suggestion of which the other 90's cars would be.
Also, retro Jerez, Brand's Hatch, Estoril and Imola in the game will be awesome. Also, 90's style yellow graphics are going to be a massive nostalgia trip, and Murray Walker narrating introductions to each car.
Another thing, apparently you can't mix decades (so it has to be 80's vs 80's etc), but can take a 2013 car onto classic circuits. However, surely that means online races in classic mode will consist of an awful lot of the same cars.
There's also going to be 80's drivers: Mansell, Andretti, Berger, + 7 others.
and 90's drivers: Coulthard, Irvine, Prost and Villeneuve + more.
I'm going to guess a lot of the other drivers will be team-mates though, otherwise there's likely to be a lot of drivers without their own cars. I'm guessing Hill will be included as they've got his car, and if they've got Irvine, one must assume a certain Schumacher might be included, especially as Codemaster's will already have a driver model from 2012.