Fair positive review of the beta from Th Register.
I haven't had much use / time for ubuntu since moving primarily to OS X. Most linux based stuff is experimented with on the Raspberry Pi and for anything windows based there is always Parallels.
Still I tend to give it a chance every once in a while. I seemed to get a lot of historic hits on this bog commenting on getting Cisco paket Tracer to work with Ubuntu. It'll probably be the same as usual, Cisco neglect to mention there are some dependancies required for 5.3.3 so you simply need to install something like WINE and packet traceer will start to work natively because the dependancies will then be installed.
I was quite interested with what Ubuntu were doing with their tablet specific features. Those did look impressive in a video a while back.