Question: I just bought a ASUS X53S. Everything works flawlessly except that I can't run Unity 3D on it because NVIDIA Linux drivers currently doesn't support Optimus. So I'm stuck with the other integrated Intel Graphics Adapter. I'm already installed BumbleBee but it doesn't help with Unity 3D thing. Will the Xorg driver ever support OpenGL and especially `GLX_texture_from_pixmap` so that Unity 3D will work with it? The Intel driver is really snappy with Unity 2D and seems to support most other X acceleration features such as smooth scrolling.

Answer: 
When something used to work, and stopped working, it is known as a regression. Regressions are usually caused by a hardware or software change that didn't agree with Ubuntu. In your case, if you have not tried it already, uninstall the Nvidia driver. If it is so broken that you can't do that, you may have to boot from the Live CD to do it. Also, by "With no unity. Or icons", do you mean it boots into GNOME, or you just see the desktop background and nothing else? Also, other info, such as the driver version, graphics card model, and other specs could be useful. Remember, on AskUbuntu, there is no such thing as too much information. Anyways, I hope this helps, and happy hacking!
To follow up on what Rocket101 said, there's a problem with the latest NVidia drivers if you have an older card. Apparently they're working on sorting them out, but they made my own system so unstable that I uninstalled them and used the noveau drivers instead. See my post here:

<https://askubuntu.com/questions/126843/clean-install-of-12-04-results-in-constant-freezes-x-org-suspected>