new update ideas
Others have already stated but I'll put my two cents in:
faster processor (true quad core processor)
more memory
new size, smaller separate model or maybe even larger to the current model
improved battery life
different form factor (as in differently designed casing)
anti reflective screen that does not sacrifice smoothness
full integrated itunes "lite" allowing smart playlist creation and id tag modifications on the fly
higher capacity, 128 gb should be affordable enough by now to fit the current pricing of the 64 gb as flash memory has gotten cheaper since the introduction of the 64gb capacity in the ipod touch 3 years ago! we haven't seen a capacity bump in years and quite frankly a device as complex and beautiful as the iPad needs this update, in fact it should have happened with the ipad 3.
price changes, 16 gb dropped, 32 gb @ 500$, 64 gb @ 600, 128 gb @ 700 (750?) Obviously wifi only pricing.
improvement in signal strength
user accounts allowing for switching profiles for family members for their own work space and customization
new improved gpu
There is plenty of ideas they can come up with and they have a professional team to come up with ideas.