A new iPhone 4S ad started airing on TV which features actor Samuel L. Jackson giving orders to Siri.
The ad does appear to be an Apple creation. The three US iPhone carriers – AT&T, Sprint, and Verizon are variously featured in title cards at the end of the ad. There is a similar ad featuring Zooey Deschanel being broadcast as well:
Apple rarely, if ever, uses celebrities in their advertising, particularly as themselves. The “I’m A Mac” ads featured Justin Long and John Hodgman. However, they were playing characters rather than acting as a celebrity endorsement. Actor Will Ferrell also did a number of iPod ads a few years back.
Source: Mac Rumors