I would like to see new or improved designs on hulls, meaning not everyone needs a .125 tank
meaning lighter weight but still structurally sound hulls, meaning more LT friendly (no obstrusive seats, better attachment points). I would like to see some propeller advances....I tried the GD 3 blades prop back in the late 80's when they introduced them and they were fine in clean water but knotted up with veggies...but I see some are now standard on surface drives. BackH20 is to be commended for the new paradigm in longtails...I see plenty of small and large rigs in southeast Asia that are pushing heavy loads with amazing speeds, many piloted by skinny operators while all I eve hear is whining from former LT owners here! 
I've been toiling with LT's since 1987, my arm is holding up fine, I want to go from a 27 to a 35 HP for better push, torque, speed when I am carrying three hunters and gear. I'd like to see more user-friendly grips, throttles, better grease zerks for the shaft housing, hex hub props for easier removal/assembly, fold-away grab bar, more efficient (and affordable) mufflers, refinements in motor mounts to reduce vibration, easier-to-work on bearing systems...just to name a few.