Rockhopper PLC is drilling as we speak..
Effectively an appraisal well for the SeaLion field to see how far it stretches and hitting a previously untapped fan system.
Initial estimates from the single drill on SeaLion indicate 170+ mmbo, though if it does stretch as far as the current well then you're looking at closer to a billion barrels.
Oil has been found and is commercially viable. It is too early to say how much but RKH have funding through 2011 for a further 8 wells.
It took 80 wells sunk into the North Sea before commercial oil was found, it is very early days in the Falklands however results are encouraging. I suspect we will see the first Falklands oil sold towards the back end of 2012.
The problem, and the direction of Argentine discourtesy, is in the transportation. All of the FI explorers are relatively small (saying that Rkh tops a billion quid now) hence they need finance to develop and explore the region. Once production starts they will need to hire tankers to deliver the oil to the nearest refinery. If the nearest refinery, due to political pressure from Argentina, is 1000s of miles away then it makes the commercial aspects tighter.
Not impossible, just less profitable overall. The recent rise in the oil price dwarfs these considerations of course.