Blizzard thinks that people feel gimped in ToL due to lack of offensive capabilities, which is obviously a pvp concern (lol resto dps in a raid). However, with talents such as http://www.wowhead.com/spell=63411 this doesn't seem to be too much of a problem. This leads me to believe that Blizz has another reason for proposing this change, other than people complaining that they never see their armor (I happen to enjoy not seeing my armor, it makes us very unique as a class).
One reason I can think of for proposing this change is that Blizz wants CC to be much more important in Cata, therefore I propose simply allowing entangling roots to be castable in ToL form. It makes a lot of sense for a magic tree to have its roots entangle a nearby enemy and gives resto the ability to CC without being too overpowered; similar to how Blizz has allowed balance to cast hibernate and cyclone in owl form.
Another reason I can think of is that blizz wants to give resto a very unique CD to use, therefore I propose a compromise that allows restos to stay in ToL form and gives them a unique CD. Spiritual Entanglement - 1 second cast, 3 minute cooldown - While in Tree of Life form, the druid becomes rooted in the spot to tap into spiritual energies of Azeroth. This ability immobilizes the druid but empowers their heals. Lasts 10 seconds.
This ability would change every spell cast while under the effect. Rejuve would have a 15% chance every tick to jump to a nearby target. Lifebloom would only lose 1 charge after blooming. Regrowth would place its hot component on 5 allies near the affected player. Healing touch would have a significantly increased critical heal chance. Nourish would renew any hots on the target. Wild Growth would have a diminished cooldown, possibly none.
This cooldown would give trees a very unique, flexible, and situtational cooldown for both PvE and PvP players, without becoming too overpowered. It would encourage trees to be intelligent with their heals and require them to decide what's more important to heal.
I quit wow recently and decided to wait it out until cataclysm, so if people really like this idea I would suggest posting it on the official forums.