WE NEED TO LET MOZILLA MANAGERS KNOW THAT WE NEED APIs FOR SESSION MANAGER: PLEASE DO THE SAME. Even if Session Manager will not be ported, there will APIs which could be used by other session managers, like Tab Session Manager, My Sessions, or Tab Mix Plus.
TO VOTE ON THESE APIs/BUGS, register on bugzilla.mozilla.org first. Then go to pages above and choose "Vote" in "Details" at the top of page. After choosing "Vote" button, next page will appear and you need to mark field next to "Vote for this bug" and then click onto "Change My Votes". Please, vote for the bugs, but do not comment on bugzilla.mozilla.org (unless you have specific information that will help to resolve the bug).