Why the nba2k9 can't play on line?

I always play nba live from live 01 to NBA LIVE 08,

now i play the nba2k9, it's very good except that it can not play with other people on line.

i feel very sad hope that NBA2K10 can do that.

come to play with many friend ,so that it can improve skill.

thank you ,do you han any comments can write ,i will thanks to you!