The MAS ff scheme is called enrich, and anyone can join. Before Feb 1 there is no joining fee [after then RM50] and you also get 2,000 reward points as a founder member.
Contact fax +603 263 3689 or http://malaysia-airlines.com/enrich
Partners, benefits, rewards are yet to be fully disclosed, but will need to be competitive with SQ & CX.
The other way is to join the Ansett FF scheme, provided you have a NZ, Australian or south pacific island address. Then you can get credit for Mas flights. If your address is elsewhere, that does not apply. Discount economy flights on Mas booked in B,Q & L classes do not accrue Ansett points, Y, M, K and above do.
Both Ansett and the new Mas schemes only give 70% of points for discounted economy fares, unlike many US schemes. Hope that this helps.