Mac Rumours rounds up some info which suggests Apple is developing its own ARM processors for future iPhone models:
A NY Times blog entry reports that Apple is indeed working on its own variant of the ARM processor for the iPhone. The information verifies what has long been speculated based on Apple's acquisition of P.A. Semi earlier this year and announcements by both ARM and Steve Jobs.
Former P.A. Semi engineer Wei-han Lien lists his current position as "Senior Manager Chip CPU Architect at Apple" in his Linkedin profile. His specialties include high performance microprocessor architecture/micro-architecture and verification. According to his published profile, his present job is managing the "ARM CPU architecture team for iPhone".