LDAP support for Windows 2000/2003 has been supported since ACNS 5.0 for LDAP queries.
If you want ADS/LDAP support that also works, its just not transparent, ie user is asked for username/password. To my knowledge its going to be like that for some time.
I've used LDAP a number of times against ADS, the only gotcha is the value you use for the username.
Mark