Certainly the "one-off" uplift in 99/00 from the oil price isn't going to be repeated...the market is now alert to the possibilities. I agree its hard to argue that any "crowding-out" from the ample supply of investment opportunities in the sector should prevent the market from rewarding the successful companies.
Although I maintain a vastly overweight position in the sector, I would not and have not suggested that it is sensible to have a sector-wide position. All my holdings are IMO in companies that hold assets of potentially substantial strategic value and, whilst a rising tide of oil prices is not going to materialise and allow every boat in the sector to be floated, there are still sufficient opportunities IMO to produce substantial returns from carefully chosen companies. I am still expecting to see returns of 50%+ pa from my own portfolio for a while longer......though whether they actually occur is to some degree in the hands of the geological Gods as well as the hands of management.