good article. for some reason people are apprehensive about embracing this as a recording tool. i have to say the only reason i kept mine was for it's midi control and recording capabilities.
you should include a few things.
firstly beatmaker. this program is of superior quality as a sampler. this is so far the best app to come out of 3rd party dev.
also, the need for and review of more dock connecting mics. this would be useful.
and maybe address the effects issues. see how much the platform can handle. could you imagine having amp modeling in one of the 4 track or 8 track programs?
and a swinging metronome? you sit down at a drum kit, put the phone on your lap with stereo mics, headphones and metronome on, record the drum track. then with high quality modeling within the program plug in your guitar, monitoring the output, and records your tracks.
that is portable recording and a fantastic tool for making demos.
what i myself would like to see most is apple opening up the dock to a midi keyboard. the iphone is already capable of producing excellent polyphonic midi/synth patches, but your only option is to use the onscreen keyboards. making the programs themselves totally unrealistic and nothing more than a toy. however, an external key board would make a portable midi studio a reality. i would love to be able to walk down the hall to my neighbors to play with a full band with nothing more than my phone and a 61 key keyboard, or smaller even for traveling. synths, organs, keys, everything you need.
i really hope more people start discussing these issues and create an atmosphere of innovation surrounding the platform. this has had unbelievable potential for the past few years and i am dumbfounded that the amateur recording scene hasn't jumped at it more.