I think MXM graphics is a great idea.
I would add a southbridge to be companion with an SoC style CPU, which would provide more USB, add USB3, and give faster SATA-3 than I understand to be included in Freescale SoC parts. The A-Eon X1000/Nemo motherboard proves the concept with an AMD sb600 southbridge. While the newer FCH parts call their link to the CPU-internal northbridge link by a different name, I suspect it would be similarly connectable, as it still appears to be based on PCI-Express, potentially with a video link in parallel. And it is relatively easy to join AMD's Embedded Developer website to obtain specs and reference designs. This is my intention for how I myself would design a PPC system today.
For other things, I would hope to see PCIe-Mini/Msata and/or M.2/NGFF slots for wifi, video decoder, etc. mini-cards, and I myself hope to see Expresscard2 slot supported as well.
I am hopeful for a backlight keyboard, which I find useful in my PC laptop. I have a work laptop by Lenovo which instead has a small LED "flashlight" in the top screen frame, which does a poor job and causes more reflection glare on the keyboard than useful visibility.
But I am very excited at possibility of modern PPC laptop, and would be happy to see anything happen, these are just some of my wish list things for consideration.