This is a good question, should they add the traditional Gnome 3 layout in Ubuntu 11.10? Linux Mint are staying with the traditional layout when they switch to Gnome 3 and Ubuntu should keep the traditional layout as well, the simpler design of Gnome 2 over Unity is why I prefer to stick with it instead of installing Ubuntu 11.10 or 11.04 with the new Unity desktop. Not everyone is enamoured with the new desktop environment that is forced on to the users of Ubuntu with the new interface. I prefer the Gnome 2 desktop, but that will be removed from the Ubuntu 11.10 repositories very soon and then you will have to use Xfce or Lxde instead. Someone needs to fork() the Gnome 2 code and support a version of Ubuntu that still uses this code-base, even though they would be sticking with GTK 2+ that would not matter, they could back-port code from GTK 3 and still bring in many of the new features of the newer GTK code.
There is a post here that gives some useful information on installing the Gnome classic desktop on Ubuntu 11.10, this involves a Gnome fallback mode that looks like Gnome 2 but is using GTK 3.0 code. I have tried this out and it is pretty good I guess, if you have not got any access to Gnome 2 then this will be a pretty good alternative for you. The screenshot to the right shows the Gnome 3 classic desktop with the Gnome 2 look featuring the two panels and the Gnome 2 styled menus.
This is to be available in Ubuntu 11.10 as a substitute for the lack of the Gnome 2 desktop, but as I have said before it still uses the GTK 3 code and is a poor substitute for the former Gnome desktop. Better to find an Ubuntu distribution that will keep GTK 2.0 and Gnome 2, as I would doubt that you could install GTK 3.0 and GTK 2, they would conflict with each other. I am using Sabayon Linux 2.4 at the moment, that has Gnome 2.30.2 and I am perfectly happy using that instead of the latest and greatest Linux desktop. If people are happy enough using one style of desktop, then why change it suddenly to something totally different just to make it look like Mac OS X?