In Starcraft 2 Beta, voice chat is available, it is very fast and it will not make any lag during multiplayer matches. Starcraft 2 has no LAN property, you can play  LAN games by just connecting Battle.net. The multiplayer games are generally very low lag rate which makes the game easier to control. Also in SC 2 Beta, unnecessary waitings are minimised  like;  pylon building time or other building construction times this makes the game more dynamic but there is a style problem in SC 2 which can not reach the success of SC original for now.