Got my refund already.
Then I bought the Steam version, can play multiplayer now

***To the mods: Request for sticky, thanks

Background (refer to these previous posts):
viewtopic.php?f=91&t=39061
viewtopic.php?f=91&t=38872&start=10
viewtopic.php?f=92&t=38917
The patch update from app store is taking too long... I should have bought the "Steam" version...

Anyway, my understanding you can still play online muliplayer with other players as long as you are all using the same version (currently still at v1600...)
So add up your name here so that we can create our mac app store version mutiplayer community (while waiting for the release from the app store)
My ALB in-game name is kllc <--- This is my "nickname". I'm still looking for the "login id", which I don't know how yet... sheesshh....
Consolidated NickNames:
1.) kllc
2.) dr_slump
3.) VanDahl
4.) CpnSocialist
5.) Benoye
How to Add Friends and Play Multiplayer with other App Store v1600 Players (tested to work with dr_slump)
If you are to use the "Add Friend" feature, I think you have to add using the "login id" (what I gave was nickname only, that's why you can't add me properly).
Unfortunately, I also don't know how to get the "login id".
Anyway, I think dr_slump is right, we should be online all at the same time, that is:
1.) I message you via the "global chat"
2.) Click my name so that you can do private message to me
3.) Then my name should appear in the "recent contact" area (lower right of the menu screen)
4.) From there, you can already add me (click the + button, color blue in the middle).
5.) Once added, you can start creating mutiplayer games / coop or versus campaigns, just invite your v1600 new friends