This is indeed something to consider carefully. Good thing is that there are multiple sub-bands, so you can switch between them to increase your air-time (testing this right now with the lmic implementation). There also is a sub-band with 10% duty-cycle.
Right now, different vendors use different frequency plans. We have some options, and choice to be made.
I’m putting together a wiki page on frequencies, bands, and channel plans, to collect all this information. Hope to have it up tomorrow. Feel free to comment.
And thanks for the links!