The DTV-pocalypse is finally here, and as broadcasters nationwide officially turn off their analog signals today and boost their digital ones, the local DTV channel line-up could be in flux for a while. A few months ago we rounded up the digital TV channels that have been widely available in the D.C. metro area for some time, but all the advice we’re reading suggests you should rescan for possibly new or different available channels at least once a week for the next little while, as things may change or shuffle around. The Post’s excellent tech guy, Rob Pegoraro, answered a bunch of questions about the transition in a live chat today, so check that out, too.