Well, as usual, there will likely be some more sounds and styles. My guess, since the E473 was a pretty big jump from the E463, at least in terms of the workflow of the instrument and the onboard effects, that the changes to the E483 will be more evolutionary than revolutionary. With that said, here is what I would LIKE to see...
A function to allow the sustain pedal to sustain the lower part of a split keyboard, if desired -- with the ability to save the choice in a registration
Upgrading the style section somewhat so, at the very least, there is a way to do a drum fill-in with only one press of a button without having to change style variation. Additional variations would be fine, but not something I need personally
Upgrading the 6-track sequencer so that, if you make a mistake when recording, you can start recording a particular track from a specific measure, instead of having to re-record the entire track from the beginning
Additional registrations -- either additional buttons per bank, or at the very least allow for a Bank 9 and Bank 0, in addition to the existing Banks 1-8, to allow for 40 registrations instead of 32. C'mon -- We've had 8 banks of 4 registrations for a dozen years now! Computer memory is cheap these days!
Dedicated line-outs would be nice -- It would allow the the on-board speakers to be used as monitors while still allowing for external amps and speakers
Move the live-control knobs back to a position right near the keyboard! Where they are now, if you are using multiple keyboards, one above another, if the E473 is on a lower level, then it might be more difficult to access these knobs. Additionally, on my E433, I sometimes manipulate the knobs with 1 or 2 fingers of my left hand while holding down notes on the keyboard with other fingers of that hand. This is impossible with the layout of the E473
And please, bring back the superior key feel last seen on the E433. Since then, the key feel on the subsequent models, while not bad, just isn't as crisp as that of the E433
Now, out of this list, what do I expect to see implemented? Zilch!
Now, Salman, can you please clarify -- What do you mean by, "Lastly, Yamaha will change the main frame like the lower model of psr-e433 or psr-e373"?