Druids can be Kitties! (and I suppose Bear-Bears...)
Shaman can be Puppies!

That makes them both amazing.

Since PvP gear has free PvP stats (PvP Power & PvP Defense), but is lower iLV than equivalent PvE gear...
You'll likely have a set of gear for PvE and a different set of gear for PvP.
It might overlap on some pieces, but in general there will be two sets.

Assuming two sets, you're not really that far behind when you use a Shaman for PvE and a Druid for PvP (or vice versa).
It is another option to consider.