Ubuntu 12.10 with code name Quantal Quetzal already started working by Canonical Developers, there may be no more Unity 2D in Ubuntu 12.10 and in other future releases. Unity 3D will use the technology of Gallium 3D LLVMpipe which allow it to perform on almost any kind of hardware. That’s why it seems likely that Unity 2D is having its last appearance in Ubuntu 12.04.
If you are those who have free time and love to test new stuffs, you can get the ubuntu 12.10 iso image via download botton below, Ubuntus are known for their ‘stability’ even for their pre-alpha releases. The credit goes to Debian which is known for rock-solid stability.
Ubuntu 12.10 is still in the beta version and have many bugs, the size of the ISO image will be large than 700MB. You can use a USB stick or a CD/DVD to test the ISO image daily build of Ubuntu 12.10. Also, dont forget to check the release schedule of Ubuntu 12.10