Metro Silver Line: Just completely forget about clapping, because it's really absolutely, positively, surely gonna happen*

* Unless it doesn't.

But with the new hopetastic administration just a few days from taking power, apparently U.S. Transportation Secretary Mary Peters took a few minutes away from packing up boxes and her "World's Greatest Bureaucrat" coffee mug to catch up on her paperwork.

U.S. Transportation Secretary Mary Peters gave the final federal seal of approval to plans to extend Metrorail to Dulles International Airport last night, ensuring that the $5.2 billion project can move forward without restrictions.

Yesterday's news marks what state, local and congressional boosters said is the government's irreversible approval of the project.

"It's an exhilarating feeling," said Virginia Gov. Timothy M. Kaine (D), who praised Peters and Northern Virginia's congressional delegation for working together to keep the rail line alive. "It's going to be a wonderful project for the whole region."

Peters's action releases the project to Congress for a 60-day comment period. After that, the project qualifies for a $900 million federal transit grant that state, local and congressional leaders have said is essential to its success.

Once the money has been released, the remaining work can proceed unfettered by federal regulatory limitations. Before last night's action, federal regulators gave project managers incremental permission to order rail cars and begin utility relocation work in Tysons Corner. But the money for that work had to come from nonfederal sources.

Sweet! We've said it before, we'll say it again: We look forward to that sunny day in 2013 2015 2020 whenever when we'll be able to board a shiny new Metro car at Wiehle Avenue and get 300 yards closer to Tysons before a track fire forces us to evacuate and hitch a ride home on the Toll Road.