Those were silly dreams to begin with RAM and CPU's require very precise timings. Every bit of trace, wire or connector will ruin that very quickly. I'm fine with I²C. Fast enough for a very broad range of usages, very cheap, very easy to connect to microcontrollers, very easy to develop. USB lacks most of those features. Heck, using I²C you can connect your mobile directly to an RaspPi or Arduino, which will be great for innovation.