"be that as it may" is an idiom meaning:
(1) even if what you say is true,
(2) although it may be true,
(3) I accept what you say as fact, but that doesn't change my opinion about it.
e.g.
(1) I am sorry about you misfortune, but be that as it may, you still have to accept the consequences of your own action.
(2) We are very close to sucessfully completing this project, but be that as it may, we would still need be extremely careful.
2012-01-27 11:28:04 補充:
Correction:
last sentence: "need to be extremely careful."
In accordance with the idiomatics of a language,it can be definited as May it be as that,which is used to express wishes&hopes eg.:-May the marriage be happy as (wished).
May it be so (in clause)is used to express purpose&wish,eg.:-May he be dead so that others might live as (wished).
may be(adv) perhaps,possibly.