Don't worry, I'll try not to make this the same thread I've seen about 100 times about how old content will be harder to solo with the squish, I am well aware that blizz promises to make it as similar as possible by scaling everything down appropriately.
However, what made soloing level 80 content at 85, or 85 content at 90 so easy was that we were exponentially more powerful, nearly increasing our health and damage by about 5 times that of the previous expac. With the squish in place, I would assume blizz would not want us to go back to our current HP/dmg we have now in MoP, so I expect a small, by steady increase with every level. Maybe twice the health and damage at level 100 than we WILL have at 90 AFTER the squish.
My whole point is this.. the reason why soloing old content is so easy now is because we have literally 100 times the health pool and damage as we did at level 60. Will the item squish make soloing level 90 content much harder at level 100 due to small increases in dmg/HP??