USB 3.0 has a maximum transfer rate of 5Gb/sec making it 10x faster (under optimal conditions) than USB 2.0, which has a maximum transfer rate of 480Mb/sec. USB 2.0 is now obsolete but as we know keyboard manufacturers have yet to provide us with USB 3.0. Both the brand new Yamaha PSR-s950/750 and Korg PA600 have USB 2.0. Keyboard manufacturers are somewhere between 7 and 10 years behind the curve, so don't expect USB 3.0 to show up any time soon on arranger keyboards. The Tyros 5 (under a different name perhaps) will likely have USB 2.0 as well. It may take until Tyros 6 - (or whatever Yamaha decides to call it) i.e. until 2016-2018 before USB 3.0 becomes commonplace on keyboards. USB 3.0 was released to the public in November 2008 and here we are in 2013 and keyboard manufacturers are still milking USB 2.0. Why invest in cutting edge technology when you can milk the old technology for all it's worth?
Why buy the cow when the milk is free? In other words, why spend money on R&D when customers continue to settle for obsolescence? The same principle applies to polyphony. 128 note polyphony became available in the late 1990's and here we are almost 15 years later and 128 polyphony is still the standard.
Yammie, Korg, Roland and the rest of them like to milk certain features and polyphony and connectivity are just two examples. And likely why it is that Yamaha arrangers still have sub-par drum kits compared to the competition. Thankfully Roland, Korg and Ketron believe excellent drum kits should be available to customers that purchase arranger keyboards. Yammie not so much obviously. Although I will say the PSR-s950 drums are a step in the right direction compared to Yammie's previous mid-range arrangers.
All the best, Mike