Haven't played the Tyros2 yet, but if it has the 'composer' feature like Technics does, that would be pretty nice.
Dad was a sole distributor in Asia for a long time, so I had tons of time playing with only Technics products, I'm so accustomed using the composer to make up different songs. Very easy to play live with those things.
I've been impressed with Tyros2's guitar voices, if the sounds are really playable and perhaps tweaked a little bit more to add realism to it, it'll be a very powerful guitar.
Next thing to tackle is realism to Saxophone's natural 'glide'. Tyros2 team tried to add realism with the 'breath' thing, but I don't think it sounds natural, if they can figure out various sounds at various velocity (as Super Mega Voice or something), that would be great.
More powerful and realistic drums, with some 'rolls' and other small fills, syncopated beats, etc.