what controls assertion signing?

[Mark K. Miller]

If metadata for an SP has WantAssertionsSigned="true" in it, but the 
profile in the relying party config on the IdP has signAssertions="never" 
should assertions from that IdP to that SP be signed, or not?

And, for my InCommon Federation friends (yes, I realize this list is more 
general than that) is there a way to have InCommon metadata include 
WantAssertionsSigned="true" for an SP's metadata?

Thanks all!

Max