The High Line opened up the final section to the public which continues from 30th & 10th to 34th & 11th. The entrance wasn't obvious since the crowds waiting to board the Megabuses obscured the gate. Here's a map from wiki:
I strolled the entirety of The High Line from 34th (between 11th and 12th Ave.) to 12th Street and Washington Street. My only advice is the walk down from the Phase III entrance going South because that entrance closes at 6pm. Today, the sun set at 6:45pm so I couldn't set up without being shooed away by the High Line staff. The final section still has a long way to go before it's completely developed. The buildings lining both sides of The High Line are still many months away from completion. With all the hype around The High Line, flocks of tourists and natives alike came to enjoy a gorgeous, sunny Autumn weekend pacing down the path.