The New Livestream is a new platform independent of the original Livestream so yes you will use different software to broadcast to New Livestream and will want to setup a New Livestream account.
To stream to New Livestream you will use the Livestream for Producers software:
http://new.livestream.com/live-video-tools
To stream to Original Livestream you will use Procaster.
-Ben
Livestream Support