Cool, I hope you're right about the increase in speeds!
Regarding the southern portion of the NEC, the stretch from New Brunswick, NJ through Princeton Junction and into Trenton is perfect for 150+ mph running. If Amtrak can't afford constant tension catenary for the entire former PRR, I'd at least like to see it installed on that one stretch!
During early Acela test runs, they routinely hit 160+ mph in the Princeton Junction area, but I guess they don't feel the variable tension catenary can support such speeds on a routine basis. But hey, 135 mph ain't too bad!