For comparison between M8 and 'others', some news on the new iPhone.
Engadget says: 3G and GPS:
The second-gen iPhone: 3G, GPS, only slightly thicker - Engadget
And several sites are saying it might haptic feedback:
LEAKED: Apple to Licence Haptic Technology for iPhone : Palluxo! Mac Dose of All Things Apple
That would mean that if you 'press' a 'button' on the touch screen, you'd get vibration like feedback to make it seem you really are actually pressing a button. Nokia has licsensed this as well, the article says.