Pally and 4x Shaman is fairly strong.

You could run one as a Healer (Resto spec, or dual-spec) for the extra dispels that only healer spec'd healer toons get.
You could also add either a Boomkin (Earth and Moon) or a Warlock (Curse), for 8% additional spell damage.
Boomkin adds an extra buff and provides B.Rez, but then you need to mess around with Eclipse rotations.

My personal best PvE team was:
- Prot Paladin tank.
- 3x Elemental Shaman.
- 1x Destro Warlock.

The 4x Shaman is definitely simpler.
But if I was building a new team for exclusive PvE play...
- Prot Paladin (Tank).
- 2x Elemental Shaman (DPS).
- 1x Boomkin or 1x Destro Warlock (DPS).
- 1x Disc Priest (Heals).