A new discovery is Steve Thomas. Apart from his newspaper work he created an awesome set of poster art. His love for vintage poster, propaganda and product art from the early 20th century, as well as his interest in retro-futuristic art from the mid-20th resulted in what I can call best futuristic posters online.
Go and see Steve's site for retro arcade series of posters as well as some marketing prints. Definitely worth visiting.