The BGS press release as linked to by the Daily Telegraph (bravo for linking to a source).
Earthquakes can happen pretty much anywhere though there are some areas of the planet where they are much more common, particularly along plate boundaries. The English earthquakes generally seem to be related to a counter-clockwise rotation of Scandinavia (the Baltic Shield) being accommodated by relatively weak areas of the crust such as under the North Sea. I feel sure that this earthquake is related and the distribution of places affected by the quake is roughly oriented NNW-SSE, parallel with the axis of the Southern North Sea rift.
Will it happen again? Yes!
Where? Almost anywhere except the same place!
Why is that? Because earthquakes release pent up stress. The area below Market Rasen is now adjusted and should be stable for the foreseeable future. The next earthquake will simply be located where there is the greatest build up of stress.
Can we predict where that will be? No, not with our present capabilities.
Could England expect the "big one" like California? Highly unlikely, the San Andreas Fault is a much bigger and more active fault system than anything we have in Western Europe.