I can concur with the above observation. I recently purchased an ASUS laptop which has AMD A6 processor with RADEON HD 6720G2 graphics card. It was working perfectly with ubuntu 11.04 Natty Narwhal (amd64 version). However when I tried to upgrade to 11.10 the graphical display stopped working. I could go into recovery mode and get a terminal but nothing I tried from the suggestions on thes forums fixed it. Thereafter I also tried to do a fresh installs of ubuntu 11.10 64bit followed by 32bit but to no avail.
My conclusion is also that the graphics drivers and the new Linux kernel 3.x are not playing well together yet. I hope this can be sorted out in time so that those of us with AMD processors can also upgrade to 11.10.