NetMeeting Replacement

Good day,

Would you provide some guidelines for moving from MS NetMeeting to Office
Live Meeting and/or Meeting Space? I work in a mixed Windows 2003/2000
enterprise environment with Windows XP/2000 clients. We're currently testing
Windows Vista. However, I've been having some trouble finding documentation
for an upgrade path to replace NetMeeting with Meeting Space. Can you offer
some ideas for Windows XP/2000 clients to connect to Windows Vista. Thank
you.

Rich Connolly