I have made all of the listed changes to the documentation for the RHEL 6 release, with the exception of the warning note which -- after general discussion -- seems to be a more general note about the issues of removing packages rather than a specific DM-Multipath concern.
The updated manual has been checked into the SVN repository.
dm_multipath has been fixed:
Verified in Red_Hat_Enterprise_Linux-DM_Multipath-6-en-US-1-18.
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.