So here is what I did in the meantime:
* Created a version for 2.4 that puts back all old compatibility stuff 
  that was removed either during the propagation set or the cleanup 
  set.
* Created a version for 2.6 that puts back just the compatibility 
  stuff that was removed in the propagation set (BOND_SETHWADDR, since 
  we got a complaint from a RH9 user).
* Removed the mention of the multicast param from the read-me.
* Raised the ABI version to 2 so the new ifenslave keeps propagating 
  IP settings to slaves for older drivers, and doesn't do that for new 
  ones that contain Willy Tarreau's panic fix.

I like this.

Chad