http://www.discoverytrail.org/index.htmlDidn't see anything here about this. The site says they are planning on allowing bikes. I'm sure it's years before a through-ride would be possible but the prospect of this is exciting.
The Trans-Am Trail (dirt version) has been available for years but it's not suited for bicycling due to the vast distances between resupply/towns. A true cross country off road route for bikepacking would be great.