The reason of this migration is that Sourceforge SVN is too low for the past year and I can't stand it any more. It seems that Google Code's SVN is a little faster.
BTW: Java2Script compiler has supported Eclipse 3.5 now. Please check out /branches/*_3.5 if you would like to. It still needs work of merging from /branches/*_3.3 ( as the major trunk for a long time ). Hope merging 3.3 will be less pain with a faster Google Code SVN.