Cept when you are shifted, you loose access to the vast majority, if not ALL the actions you used to be able to take.
There are 2 flaws with that. One is you can't use a staff as wizard except with wizard powers, period. This is true for all classes. Even if the implement is the same type of implement, the only thing that gives you a right to use an implement at all is that you have a class feature, and that feature always restricts you to using it with your own classes powers. OK, I see that Initiate of The Old Faith does get you past that one...
Secondly, you have NO effective melee attack when MC into Druid, except a once-per-encounter use of a druid at-will.
You can OA (sort of, technically not, but the difference is unimportant really) once per encounter, or you can make an attack, once per encounter. Once you burn that use, you have NO melee ability at all.
Now, that doesn't negate your ability to leverage Wild Shape into an extra minor action shift every other round, but it is at the cost of a minor EVERY round, which does put a bit of a crimp in it. IMHO you are not doing badly, the MC Druid has a bit of utility, but it is a pretty small benefit for the cost of a feat overall.
I would think there are better ways for a wizard to use a feat slot in general. There would seem to me to be superior MC options as well, generally. If it fits with your character concept, then it isn't too bad and you get to have fun with it. Other than that I'd call it not THAT great.
Curious, what is the Melee Basic Attack of a Druid in wild shape? I ask because if you multiclass in to Druid, and have only one at-will power that can be used 1/encounter, then what do you do otherwise? Do you just have the MBA, and what would it be?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.