if you want it to be more powerful, expect a beefier cooler to go with it. so it wont be lighter unless its very efficient. while older games would probably make use of the better hardware, theyd need patches to optimise performance and get their 'full' potential which i doubt will happen for most games.

if you want a longer battery, then doubling the screen resolution is a great way to make sure that doesnt happen. theyd have to fit in a larger battery, which again, is extra weight. and when so many games often run inconsistently at 540p-720p, youd need a considerably more powerful chip to reach 1080p/30, which will drain more battery.

unless the joycon lawsuits actually win against nintendo, i doubt that theyd effectively admit fault and change the design. theyve had 4 years to change and best theyve done is blatantly hide their joycon repair service, while often not honouring it in many places. until they pay out, dont expect them to change a thing.

the connectivity points are great. while id love to see bluetooth enabled for headphones, theyve not done it in the past 4 years despite it being hardware capable and functional https://www.xda-developers.com/nintendo-switch-android-hands-on/

while wistful speculation is fine, we'd be better off tempering our expectations.