In an interview with the Wall Street Journal, Apple CEO Steve Jobs confirms that a "kill switch" exists for malicious iPhone applications justifying it as a necessary safeguard against a malicious program (i.e. one that stole private data) that might slip through the approval process at the App Store.
Hopefully we never have to pull that lever, but we would be irresponsible not to have a lever like that to pull.
More compelling, however, was Jobs acknowledgement that users have downloaded more than 60 million applications since Apple launched the App Store on 29 June 2008:
If sales stay at the current pace, Apple stands to reap at least $360 million a year in new revenue from the App Store, Mr. Jobs said. "This thing's going to crest a half a billion, soon," he added. "Who knows, maybe it will be a $1 billion marketplace at some point in time."
Jobs also briefly addressed removing the US$1,000 I Am Rich app (it was a "judgment call") and made an interesting comment about how mobile phones are now differentiated by software as opposed to "radios and antennas and things like that."