From what I've learned of hardware engineering (basically by colocation osmosis here at a large Finnish handset maker), it's that the needs of RF performance al

From what I've learned of hardware engineering (basically by colocation osmosis here at a large Finnish handset maker), it's that the needs of RF performance alone make this thing a near impossibility, at least unless the radio and antenna portions of the phone are considered to be "off limits" for modularizing. Every piece of hardware added to the phone affects RF performance by virtue of its being made of matter (that isn't RF-transparent) and being in close proximity. If it starts emitting or being affected by electromagnetic waves, well that's a whole new layer of pain to deal with... Maybe...maybe...if you wanted to consider the radio and antenna fixed, and bring back the old external antenna that would be forever unobstructed by new bloks...