Some great questions in here:
First, I am not a lawyer, so as always, any advice is prefaced by "consult your attorney for specifics to your individual application".
Tha t said, here are my beliefs, based on understanding of MPL v1.1 (the current version as of this date).
Are we supposed to acknowledge use of the OSMF swc and who holds copyright somewhere, say in our SDK docs? If so, where is the required acknowledgement text?
The MPL requires (under section 3.6) certain notices as part of any distribution of covered code (code which is granted under the MPL license).
You must include the text of Exhibit A in each file of the source code. For the case where you are not modifying any source code, these exhibits should already be in place. Inclusion of a similar notice within the SDk docs would be a useful guard for compliance.
Do we need to inform our users that the SDK contains OSMF?
Section 3.6 (covering distribution of executables) states that you must include a notice stating the availability of the source code covered by the license, including where and how to get it. You need include this in the executable version, related documentation or collateral. You must indicate that any terms that you distribute your program under have no effect on the rights and terms of the covered code (in short, since you are moving under MIT/X, you must indicate that the OSMF code is only contained and available under the MPL v1.1. And (copying from the license, cause it's deep legal) "You hereby agree to indemnify the Initial Developer and every Contributor for any liability incurred by the Initial Developer or such Contributor as a result of any such terms You offer."
Do we need to make the unmodified OSMF sources available (my reading of the MPL suggests not)?
No, as long as you meet the terms in 3.6 and indicate where and how to get it.
hope this helps,
Director, Open Source and Standards
Thanks for this - let me chew it over and see if there are any outstanding questions.
BTW - kudos - it's truly great to get such a prompt response on this kind of query.