The Kernel 3.3 is already getting close. Will the Ubuntu development team add it to their upcoming release? That Kernel fix the overheating issue of new laptops!
From this answer the power regression fix has been backported to the 3.2 kernel that will be used in 12.04.
From the release schedule you can see that 12.04 is already in beta, so the kernel version will not be changing at this point, as that would be a big change that might well introduce regressions.
Linux 3.2 will be the kernel that ships as the default kernel for 12.04.
As with 10.04 the kernels from the next releases (Q,R, and S) will be made available as packages in 12.04.
In 10.04 these packages were named something like linux-image-generic-lts-backport-oneiric. For 12.04 they'll be named after whatever animal and will ship whatever kernel from that release is supported.
So whatever Linux kernel happens to ship in the Q, R, and S releases will be built for 12.04, put in a PPA similar to what is done here. These kernels will be supported for the life of their respective release, so each one is release is supported for 18 months from their publication, while the stock kernel will be supported the full life (5 years) of 12.04.
From this answer the power regression fix has been backported to the 3.2 kernel that will be used in 12.04.
From the release schedule you can see that 12.04 is already in beta, so the kernel version will not be changing at this point, as that would be a big change that might well introduce regressions.
Linux 3.2 will be the kernel that ships as the default kernel for 12.04.
As with 10.04 the kernels from the next releases (Q,R, and S) will be made available as packages in 12.04.
In 10.04 these packages were named something like
linux-image-generic-lts-backport-oneiric. For 12.04 they'll be named after whatever animal and will ship whatever kernel from that release is supported.So whatever Linux kernel happens to ship in the Q, R, and S releases will be built for 12.04, put in a PPA similar to what is done here. These kernels will be supported for the life of their respective release, so each one is release is supported for 18 months from their publication, while the stock kernel will be supported the full life (5 years) of 12.04.
Here's a reference for 10.04:
You can install that kernel by yourself. Here is guide for example: http://www.upubuntu.com/2012/03/how-to-install-linux-33-kernel-in.html
Beware, all changes you are doing is your own risk. I recommend to uninstall proprietary video drivers before install.