The key components likely making up this stack in the "Precise Pangolin" release for next April are:
X.Org Server 1.11 - xorg-server 1.11 has been out since before the release of Ubuntu 11.10, but they didn't ship it then over not wanting ABI breakage with the graphics drivers and needing to wait around for AMD / NVIDIA (but namely AMD with their Catalyst driver) to support the new ABI. By the time Ubuntu 12.04 LTS is released, xorg-server 1.12 will likely be here, except they will still be on version 1.11.
There's some interest in seeing X.Org Server 1.12 in Ubuntu 12.04 LTS, since the various input / multi-touch work should finally land. If 1.11 is still in use, the input work will have to be back-ported to its code-base. In X.Org Server 1.12 there might also finally be RandR 1.4, which would provide per-CRTC pixmaps and the ability for NVIDIA to finally support RandR 1.2+ from their binary blob. This would be really nice too, but we probably won't see it until Ubuntu 12.10.
Linaro also has some various ARM-related DRI improvements they are wanting to land in X.Org Server 1.12. So there's a chance we might see 1.12 ready in the Precise Pangolin, but more than likely it will be version 1.11 with a lot of patches back-ported on top.
Linux 3.1/3.2 - The Ubuntu kernel team will be figuring this out on Wednesday, but they are debating between the Linux 3.1 and 3.2 kernels to be used in Precise. Hopefully it will be the Linux 3.2 kernel and that's what it's likely to be, but there's a chance they may be ultra-conservative and ship with Linux 3.1 instead.
Mesa 7.12 - Canonical is likely to ship Mesa 7.12 (or it will be Mesa 8.0 should the OpenGL 3.0 support be complete before year's end). However, they are reserving the right to potentially still rely upon Mesa 7.11 if the 7.12/8.0 release is very late or not up to their expectations. This would be a huge bloody loss if 7.11 is still in Ubuntu 12.04 LTS. The open-source Mesa / Gallium3D drivers have been advancing at a very brisk pace and there's already so many improvements in Mesa Git over 7.11, even back in October the Git snapshot was far superior to the 7.11 release. Even if 7.12/8.0 is late, it would be better shipping a Git snapshot as overall the improvements have been going great and Git master is relatively sane.
DDX Drivers - The X.Org drivers to be included in Ubuntu Precise will be whatever's the latest at the time of feature freeze in February. Likely the latest stable xf86-video-intel and Git snapshots on the Radeon and Nouveau drivers.
Wayland - A Wayland Display Server session for Ubuntu will be held later this week in Orlando.
Old Mesa Drivers - Ubuntu developers are looking at packaging up the old Mesa 7.11 drivers that were dropped in Git recently (VIA, Savage, Matrox, etc) and offering them through a mesa-old-dri-drivers (or equivalent) package. Mesa developers have kept their OpenGL driver loader backwards compatible so that these defunct DRI1-only drivers can still be loaded on a modern Mesa stack without replacing it completely.
Updates During The LTS Cycle - With Ubuntu 12.04 LTS being supported on the desktop now for five years, Canonical is more worried about enabling new hardware support after the April release. What the plan is now is to backport new kernels and the X/Mesa stack to 12.04. In the Ubuntu X world, what they are looking at doing is simply rebuilding the latest Mesa/X packages of new Ubuntu releases and drop that into the Precise repository in time for the LTS point releases. In other words, the stack of Ubuntu 12.10 would be rebuilt and dropped into the 12.04 repository, 13.04 packages would be rebuilt and pushed back into 12.04, etc.
This is a more sane approach than trying to back-port all new hardware enablement to the LTS versions. The Linux kernel is also expected to be upgraded in the LTS cycle in order for new hardware/driver support.
There's still some items to be figured out with this new LTS management, such as how to let the user upgrade their X/Mesa stack in Ubuntu 12.04 but might not want to move to a newer kernel, or restrict all drivers from being upgraded if they are concerned about regressions, etc. This will hopefully be figured out in other UDS-P Orlando sessions this week.