IANAL. I'm afraid you have it the other way around. It is easier to switch from permissive licenses (MIT / 3BSD) to compatible restrictive license (MPL / xGPL) than vice versa (xGPL to MPL / MIT) without a CLA.
We do have a CLA, and put it in place for this very reason. It is more complex legally, but I meant more in terms of the community. Better to make people happy by going less restrictive over time then to start out with Apache and switch to something more restrictive and upset a bunch of people.
Glad you're going Apache, though.