The March 11 earthquake was a 9.0, off the coast of Miyagi prefecture. The earthquake on the news from late Thursday night (mid morning on the US east coast) was a 7.4 in the same area. (Edit: later revised to 7.1. Source: NHK World) Biggest aftershock to date, but not as large as the Big One. There was a tsunami advisory, but I don't think one ever happened. If it did, it was small, perhaps a meter or less. A meter of fast-moving water is dangerous, but not as scary as the thirty meter wave from March 11.
We are fine! Please don't spend your anxiety on us, we are as far away from this earthquake as Washington, DC is from New York City. (230-ish miles) Be concerned for the people of Miyagi that are already living in evacuation centers because their houses have been demolished by a giant tsunami and just experienced an earthquake 80% as big as the original big bad. There were some injuries (I don't know how serious), but no deaths as far as I'm aware. (Edit: 4 people died, 141 were injured. All four were elderly; one may have died when the power went out on her breathing apparatus, one fell from her 3rd-story balcony, and two men died in a hospital, possibly from heart attacks. Source: NHK World)
There were power outages and some water/gas leaks in the immediate area, but the nuclear plants, including Fukushima Daiichi, haven't noticed any abnormalities as a result of this earthquake. Highways and train systems were closed, but I'd be surprised if they're not open again and functioning normally.
This aftershock (I'm still not totally clear on when earthquakes stop being aftershocks of a previous quake and start being recognized individually) was curious in that it had a very distinct line with my cross section of friends in Japan. My friends in tall buildings in Tokyo said it was the worst aftershock they've felt; at my house we just had some house weebles that seemed to last for a long time but weren't scary intense; a friend at Camp Zama (25 miles southwest of Tokyo) said she didn't feel it at all; a friend near Mt. Fuji (65 miles slightly-south-but-mostly-west of Tokyo) noticed but her boyfriend slept right through it.