I don't think Ford will be giving the Raptor a longer bed as they want to keep wheel base as short as possible. That is most likely to avoid high centering.

The 5.5" is fine for day to day stuff, and with the tailgate down it works for bigger stuff.

I love my Raptor's style and capabilty and the 6.2 motor is just beastly, and gets decent milage when you keep your foot out of it. I am averaging 16mpg or so now that I have changed my driving style.

I hope that helps.