Disklavier

What are the Mark IV features you would most like to see in an upgrade
kit for older Disklaviers?  Would it be enough to have a device that
supports playing Yamaha (and competitors') CDs from a CD or MP3 player,
plus support for streaming music from a laptop or PC (including
Disklavier Radio)?

Or is the tablet/PDA interface absolutely essential?

My person opinion is that the expensive tablet and PDA hardware (though
cool today) will be hopelessly obsolete in just a few years, so an
upgrade based on adding so-called "analog MIDI" inputs would be the most
future-proof way to go.  This would let you operate your Disklavier from
any current or future audio source, including MP3 players, wireless
links, central home audio systems, streaming from the Internet, etc.  
Analog audio inputs on a Disklavier would work even 25 years from now
when USB and wireline MIDI are long-dead relics from the past.

Mark Fontana