Rage is near completion, doom 4 is in development and Id said they don't need another new franchise for another decade. They have Quake live right now but soon they might think of getting a new QUAKE. What are your ideas about the next Quake?

Here is what I think

Quake is Id's futuristic military shooter, people seem to be growing tired for modern combat now. Many studios are planning to make a jump to futuristic shooters in the coming years. Why should Id not leverage what they have had to so many years right now. They have a pretty good Universe and story setup. They are multiplatform now and they actually have multiple dev teams.

Id should jump the gun and make Quake 5 soon. make it a reboot start back from Quake wars, as in the original strogg invasion. With Id tech 5 or 6 whatever they have when they start development. They can create massive battlefield. Lots of GDF and Strogg fighting each other. They have an amazing arsenal from Quake wars to use.

So here is the break down
1) Large scale battles lots of soldiers and vehicles battling at once
2) Multi location battle, not only deserts but cities and forests too
3) Both strogg and GDF story lines.
4) Quake wars like multiplayer.

Id has definitely taken an interest in developing the story this time around with RAGE and by the look of it they will continue to do so.
Imagine having massive tank battles where a very large Tank commander just drops out of the sky to ruin your day.
Or while paying the strogg having the ability to call a violator strike from space. As in you are like a strogg connected to the violator cannon sitting in space. Forget about the COD gameplay where a gunship would shoot enemies down. You are sitting in space and calling in violator strike all across the planet.

There can also be mission involving spaceship battles to thwart strogg ships in space. You can even add some sea battles for fun.
The way i see it the story can roll like you start as strogg, you attack earth and then you keep winning till some point. This is when story shifts to humans and you start owning the strogg and send them running back.
You can also have a lot of scenarios involving you being either the makron or a tank commander.

In short, this is ID's military shooter and I feel they should treat it like one by creating the feeling of a global conflict and a more big army like feeling instead of a one man army feeling