In responding to a developer bug report, Apple has reaffirmed that its Siri virtual assistant will remain exclusive to the iPhone 4S for now. Citing a person who submitted a bug report suggesting that Apple release a paid version of iOS for iPhone 4 and fourth-generation iPod touch users that would include Siri, Michael Steeber reports that Apple responded with a simple statement: “Siri only works on iPhone 4S and we currently have no plans…