Did The Earth Move for You, Baby?

Auckland was hit by an earthquake on Friday night.
Oh, really?
GeoNet said the 2.9 quake (!!!) at 9.09pm was 9km deep, similar in force to about five aftershocks in Christchurch that day. Residents reported shaking across the city, and social networking comments covered the entire spectrum:
Worried: "Just felt an earthquake in Herne Bay?!? What the...".
Joking: "State of emergency declared in Auckland after 2.9 quake disturbs glasses of pinot and causes machiatos to spill over cup tops."
Flippant: "It wasn't an earthquake - the taniwha just farted."
Cynical: "Harden up! Stop going on about a 2.9 quake like it’s news."
We live in a volcanic country that shakes daily. The GeoNet site shows there were seven quakes in NZ on Friday, including a 4.7 off Te Anau…which was not reported at all.
And that’s really the point, isn’t it? What IS news? Is it a report of something happening…or, more selectively, a report of something interesting happening?
A shake that felt to most Aklders like a truck passing, that slightly moved the tv remotes on the coffee table, is a non-event to beleaguered folk in Christchurch. But to those who have perhaps never felt a quake, it may have been a frightening portent!
Consider too that very emotive word, earthquake. After Christchurch’s disaster, all of NZ has a definite EQ image in mind. But I was educated that a shake of this size was merely a tremor, that a quake was something quite different. The dictionary defines a tremor as "a relatively minor seismic shaking or vibrating movement."
Is there a recognised seismic point, beyond which something officially becomes an EARTHQUAKE?
Is there a recognised journalistic point, beyond which something officially becomes NEWSWORTHY? 
PS: 02 July 2011 - Weatherman Philip Duncan's view on why this tremor was worth reporting...