Translated:

Currently, on a certain website, information that a LAN crack for SC2 has surfaced. A lot of players have confirmed that the crack does indeed work but we here have yet to test it. If you are interested, you can try it out. The originator is from China and we here feels it goes to show China's great ability to crack software. Even though cracking software is surely not a good thing for the original creators, judging from the current state of SC2, the LAN crack will help in spreading and popularizing the game more quickly.

Method:

1.) You need a version 1.2.2 Taiwan client that has not yet been cracked by Raszerd. If you have problems upgrading or patching, you can find help at the following link:

http://u.115.com/file/f783fb2829#

Note: this has not been tested on the US or EU clients yet.

2.) Download XX connector (?) patch.

http://u.115.com/file/f3a96bff54

After uncompressing, you will have 2 files. Place the "Starcraft II" file in the SC2 root folder and over-write. Place the "Blizzard Entertainment" file in C:\Documents and Settings\All Users\Application Data (windows XP) and over-write.

3.) (There is a lot of technical talk from here on out that I cannot fully translate since I am not experienced with this but I'll try).

Modify Starcraft II/config.ini, set the IP address to whichever computer is the host server (?), and run StarCraft II\MySC2Server\MyServer.exe on that computer. Start the game.

Note: The computer which is set as the host server must have a public network IP (?), it does not work with a router (though it works with a virtual LAN network).

4.) For the log-in information server-side, use father@v.gg as the account, iloveyou2 as the password. For the other computer, use mother@v.gg as the account, iloveyou2 as the password. After logging in, wait for 5-seconds. Use father to create game and invite mother.

I found news !
you must have the english client. ( patch 1.3.0 )
you can only play on 11 differents maps
you can 2v2
Works on 7 / Vista / XP 32 bits, not 64 bits ( driver not portated yet )

Found there ( and link for download ) :
http://sc2bbs.uuu9.com/viewthread.php?tid=2389852&extra=&page=3
tested of course !
Not for Mac of course