The Amador Foothills is currently under lease by RRC (Recreational Railroad Coalition) and all maintenance duties on the line are assumed by volunteers of the motorcar community... RRC regularly has work parties, and of late has or is very close to reinstalling the west leg of the Ione wye. These work parties often turn into an impromptu motorcar run up the line and back once work has been completed for the day, which explains the shine on the railhead.
RRC's press release on the AFRR acquisition can be found
here.
RRC's homepage can be found
here.
I'll defer to someone who keeps better tabs on the NWP, but I don't believe there have been any official rail movements over the line since the 2001 shutdown. The repair work being done in and around the Schellville area has already been paid for, as I understand it, and includes wash-out repair, culvert repair/replacement, signal repair/reactiviation, etcetera... I don't know if this funding covered the vandalism incurred by the Brazos drawbridge, however.
Again, defer to those 'in the know'...