A recent Apple job listing that we just discovered reveals that Apple is looking for a low level iPhone programmer with detailed knowledge of the ARM processor including its NEON vector unit.
The successful candidate will have excellent understanding and knowledge of processor architecture, specifically ARM and its vector unit NEON. Additional Intel SSE or PowerPC AltiVec is also very helpful. Being able to use processor micro-architecture to write and deliver fast routines is an essential attribute.
NEON is an extended instruction set similar to Intel's SSE or PowerPC's AltiVec which can accelerate multimedia applications. What's interesting is that NEON is the marketing term for the most recent version of these extensions specifically for the ARMv7 Cortex processors. Apple presently uses the ARMv6 processor in the iPhone and iPod Touch which does not appear to offer NEON. The obvious reason for Apple to be seeking a programmer with this expertise is that they must be optimizing the iPhone OS for the new Cortex processors.
We've previously speculated that the Cortex processor would be the most likely candidate to power the next generation iPhone. The Cortex is also capable of multi-core variants though its not entirely clear how soon these will be commercially available. Palm's Pre is also based on a version of the Cortex processor. The presence of these sort of extensions could also be leveraged to provide users with faster/better multimedia functions including the rumored video recording, processing and editing capabilities.
In fact, another job listing reveals that Apple is also hiring for someone to deliver "cutting edge embedded video processing". They are specifically looking for someone with experience in real-time media and networking applications over Wi-Fi and cellular networks which would suggest an iPhone implementation. Obviously, all of these listings reflect unfilled jobs but can provide a hint into what Apple is presently working on.