Yes - it is a directly viable solution for 12.04.
You need to be aware that both gnome-panel
and indicator-applet-complete
(the key packages behind gnome-fallback) are part of the Universe repository. Thus it is up to the community to maintain the integrity of these packages, not Canonical itself.

I would surmise that since the Ubuntu developers included the following, this already shows the commitment to this solution:
- the backport for ubuntu indicators,
- fix to include Compiz as the Window Manager by default
The question of "problem-free" is crystal ball-gazing - not something any of us can foresee.
For more information on how to revert to gnome-classic:
How to revert to GNOME Classic Desktop?
There are plenty of panel-based alternatives such as Cinnamon, XFCE & LXDE for you to consider as well.