With the emphasis clearly placed on seamless "dynamic" advertising (read: no billboards in fantasy titles, etc), game publishers and advertising firms will be able to buy and sell space within games in order to reach the "elusive 18-34 male" demographic. They will be able to do this through Sony's in-game advertising partner, IGA Worldwide. This partnership exists with both SCEE and SCEA, so expect to see advertisements appearing on both sides of the pond.
The first company to jump on the bandwagon is EA, who has announced a multi-year deal with IGA Worldwide to include dynamic advertisements within EA's broad range of titles. This will include Madden, NBA, NASCAR and NHL as well as games such as Burnout and Need For Speed. Intriguingly, these adverts can be updated in realtime, "keeping ads fresh and relevant to each gamer" whilst maintaining "an authentic gaming experience." We don't really have a problem with adverts within games, as long as they truly are seamless (much like the product placement in MGS4). Hopefully this will make the PS3 an even more attractive platform for developers.
[Via Press Release]