Things are so bad at the moment,i do think that they could have made a cut elsewhere so that the public could see a worthwhile saving in their pockets.I cant see how we will see the difference with this cut.
Oil prices are high because demand is high now that countries like China are developing and buying more of it (though speculators did have something to do with the sharp rise passed £1 per litre earlier in the year). The oil producing countries could pump more out, but that would mean they'd run our faster too.
The tax on petrol could be reduced, but the government would have to raise the money it gets from fuel taxes in some other way. Would you prefer higher income tax or maybe an increase in VAT? Alternatively, government spending could be reduced, but which services would you be happy to see axed?
Ultimately our need for oil puts us at the mercy of the countries which produce it (now that North Sea oil seems to be peaking). We need an alternative. We haven't enough land on this crowded island to grow enough crops for biofuels. Maybe the answer is to harness the three things the UK does have in abundance - wind, rain and whinging!