I think what a lot of you guys are forgetting here is the ROW is still private property owned by GWI.
What they do with it is really up to them. The state can't just come in and turn it into a trail - not without going through eminent domain proceedings unless they deed it to the state. The line does have value in terms of scrap (rails, spikes, plates, relay ties, etc...), reuse as a utility right-of-way, etc. It could be sold off in pieces to private individuals, adjoining landowners, utilities, etc.
Many old ROW's are barely recognizable as former railroads that have become overgrown with brush over the years so it's not an automatic assumption that it'll become a rail-trail. Trails take years to plan and develop.
As an example, the Conrail Falls Road Branch between Rochester and Brockport was salvaged 15 years ago and not a thing has changed... all the structures are still in place, the ballast is still there. In fact CSX still owns all 12 miles of it and there's been very little noise in terms of solid plans for reusing it.