I think that because the tobacco won't be on the cars anymore that other key role sponsors are going to play a big role, Im thinking about tire company's such as Michelin and Bridgestone, their on the car now I know, but what I mean is like big advertisements on the car, big B for bridgestone on the Ferrari for example.
An other interesting idea would to look at the petrol companies which support the F1 teams, you would have more Shell advertisements on a Ferrari, Mobil on a Mc Laren and so on.
F1 always has alot of other options.
Coca Cola was already mentioned, why not, I think that more big companies that are non-tobacco should go in F1, I think that it would be alot more interesting if you would see Coca Cola, Microsoft etc etc..