I then starting thinking about other ways that the rules would allow some kind of shapeshifting ability.
Puppets and PossessionsPoking around the rules, I ran across the Possession and Puppet advantages. For 100 points, Possession lets your mental abilties take over another person's body in a soul jar effect, and for 5 points, Puppet lets you designate an Ally as someone who can't resist Possession attempts. The Parasitic limitation allows you to have a physical body and Possess the bodies' of people that you can move into and use their bodies as a meat shield against attacks. Possession (Assimilation +10%, Parasitic -60%, Puppets Only -30%) , Permeate (Possession Puppets) , Ally (100%, Constantly x4, Summonable +100%, Minion +0%) , and Puppet (Summonable Minion)  lets you effectively shapeshift into a single alternate form for 70 points, by summoning the puppet and physically possessing it. The shapeshifted form is a 100% ally, and since Puppets and Minions both basically need to have IQ0, there's plenty of available points for buying useful advantages such as Unkillable 2 and Regeneration. Additional alternate forms cost either 45 oinbts (for an additional summonable puppet ally) or 9 points (for an alternate ability ally if the GM allows that). That's for the ability to spend 100% of a character's points on the alternate form; less capable alternate forms would be cheaper.
Going by the Puppet/Possession route, the 125 point apprentice druid spends 110 points to turn into a bear, while the 250 point druid pays 70 points, and the 500 point master druid pays 38 points. That's a lot more affordable, though it has some disturbing implications at the upper levels. Being a shape changer who can turn into several different, highly competent forms is surprisingly affordable on a 500 point budget, and is even more affordable on a 1000 point budget, and in both cases, the alternate forms scale in capability.
At surprisingly cheap levels, Morph also becomes affordable. Modular Abilities 40 (Cosmic Power, Social Only +0%, Only Allies with Summonable and Minion -50%)  and Modular Abilities 5 (Cosmic Power, Social Only +0%, Only Puppet -50%)  allows you to unfailingly summon any 100% ally and turn him into a Puppet, and with Permeate/Possession combo above , that Puppet can then be parasitically possessed. For 275 points, that's a form of Morph that completely scales with the character point level. For another 200 points, another 40 levels of Modular Abilities would be enough to get 150% allies and be able to Morph with more points than the base character.
Abusive? You Bet!So clearly this little thought experiment demonstrates a good way to break the game, but does it illuminate anything about how much shapeshifting should cost? Or does it just demonstrate that the costs of an Ally is too cheap in 4e, just like it was too expensive in 3e? I think it's more of the latter, but I do think that shapeshifting costs too much.
Bruno has suggested that the base shapeshifting advantage should "cost 25 points, take a single Concentrate to transform, and should not automatically revert with unconsciousness." Taking extra time or reverting should be limitations that reduce the cost. I think that the implicit Accessibility limitation of an alternate form should be -20% or maybe -30%, not -10%. Taking these ideas together, the cost of turning into a 187 point bear should be 175 or 156 points, not 183 - or as low as 155 or 136 points with enough limitations on the base shapeshifting advantage.
That still doesn't help the druid enough to make shapeshifting into combat forms a viable tactic. But it might make it affordable to shapeshift into scouting or transport forms, even for apprentice druids.