Ridership is up in part because of higher gas prices, in part because more people are simply returning to train in general (read, they're riding LRT, commuter, subways, etc) and decide to try Amtrak too, and probably in part due to better time keeping. Although the latter is debatable, since time keeping has only improved in the last year and a half or so, while ridership has pretty much been in a steady climb for the last 10 years.1. Ridership is up with no reason given for why but the very next point is that on-time performance is up. However, this is acknowledged as being tied to the recession, which is presumably a temporary condition. What will keep trains on-time in the future? What will keep ridership levels up once on-time performance resumes its usually dismal levels?
As for what will keep trains on-time in the future, it's not just lower freight volume that is responsible for better time keeping. First, Amtrak took UP to court over its timekeeping, and UP capitulated and agreed to improve things. Then there is the bill passed by the Bush Administration that along with the PTC mandate, also for the first time gave the FRA some actual teeth to levy fines against freight RR's that excessively delay Amtrak. The threats of those fines caused a few of the lingerers to wake up and take notice of things.
Finally, the RR's seem to have finally come to the conclusion (in part probably due to Matt Rose of BNSF) that they will not be able to make the needed improvements for the future without some government help. The Fed won't be helping those who don't play nice with Amtrak.