This is no way to answer such an important question that most potential users will have - let's face it, there's a lot of people who will want to use this for open source, but a lot more who will want to use this for commercial apps. To ensure Meteor's wide-spread acceptance, you need to clearly answer this question on FAQ page, and not with "we need to have a conversation".
Their preference is that the library be used under the GPL. That is their choice and it is a fair enough choice. But they also acknowledge that some entities can't accept that for one reason or another, and are willing to be flexible. Very flexible: instead of saying "this is our commercial license, deal with it" they have said "tell us what you need, and we'll see what we can do".