If I were to try my own hand as an apprentice in the fine art of debian-legal license analysis, I might say the following <grin>:
DFSG 1: Free Redistribution Section 3c gives the right to use it in a collective work. DFSG 2: Source Code Not specifically addressed here (at least in terms of "preferred form for modification"). I guess we would have to look at each work licensed under this license individually to see if it includes something that we would deem as "source". It seems rather BSDish in that a person that receives it would be free to distribute it without "source". DFSG 3: Derived works 3b provides this, and 4b develops it. 8a provides the relicensing aspect. DFSG 4: not applicable (no restriction on source code is being made) DFSG 5, 6: No discrimination There is no clause about commercial restrictions or any such thing. DFSG 7: Distribution of license 8a meets this DFSG 8: Not specific to Debian Clearly this is fine here :-) DFSG 9: Software contamination Wording is fairly clear that the license of an individual document does not hinder a collective work.