Yesterday, the MTA revealed to the public the five developer bids for the West Side Rail Yards. There will be a 2-week period of public input , and then a committee of representatives from the MTA and the Hudson Yards Development Corporation will make a recommendation to the MTA's Board.
The northern 1/3 of the High Line runs through the Rail Yards site. Three of the five development proposals (Brookfield Properties , The Related Companies , and Extell Development Corporation ) preserve it fully.
Tishman Speyer  preserves part of the High Line but demolishes the spur over Tenth Avenue and part of the section along 30th Street.
Vornado Realty Trust and the Durst Organization tears down most of the High Line at the Rail Yards, replacing it with a futuristic aerial walkway called the "skyline".
No matter which Rail Yards proposal is selected by the MTA, these plans will certainly change later in the process, so even the proposals calling for full preservation of the High Line could end up partially demolishing it. And as the New York Sun points out, the MTA has not released any of the financials. 
Read FHL's E-Newsletter about the public release.
And CB4 has some background on the Rail Yards site .