There's a huge amount about this story that is perplexing and a great deal about the purported mineral treasures that could completely -- eventually -- transform the country.
So let's consider a few of them.
It's easy to think, well, there you go. This country can finally get on its feet and become reasonably wealthy and start developing, without the need for drug production and foreign aid. And maybe that will happen. But remember, vast natural resource wealth discovered in undeveloped countries has, to put it generously, a very uneven record of producing benefits for the countries as a whole. Quite a few states in Africa have vast natural resource wealth, whether it's diamonds or precious and semi-precious metals or oil. Look how well it's worked out for them.
The unfortunate but very common pattern is that extractable natural resources produce autocratic, often kleptocratic, regimes, ruling by violence, which reliably get the stuff out of ground and into the hands of more developed and wealthier foreign countries. You can come up with morality tales about exploitative first world countries but a lot of it is structural -- tied to the scale of the wealth involved, the relatively limited involvement of the local population required to get the stuff out of the ground and transformative political effect of the wealth on offer.
In any case, even the resource rich countries that don't go the way of ... say, Zaire/Congo still often end up with tons of wealth going to a relatively few people with little in the way of real economic development of the rest of the country. And the amounts of money you can get from running things are so great that there's usually a civil war or other sort of violence and turmoil waiting in the background.
So not to say it's a terrible thing that Afghanistan may turn out to be a rich country in a few decades. But the record of countries that hit it big in this way is quite uneven.
Next, just how big a survey team do we have operating in Afghanistan? And how recently did they find this stuff? The article say that the Afghan government and President Karzai "were recently briefed" on the discoveries. Afghanistan's a pretty out of the way place. But it's not like it hasn't gotten a good bit of attention from great powers in the past. First the Brits, then the Russians, now us. So no one else ever looked or they didn't find anything. But what I assume was a relatively limited geological survey turned all this up? The Times article does gives a degree of explanation -- the Soviets started looking but then shelved initial surveys as they were leaving the country, maps were hidden for decades and then progress remained fitful even during the last decade of American hegemony.
I'm not saying it's not true. But this does seem a little out of the blue. And with so much in play right now about the future of the US mission in the country, the timing of the revelation is enough to raise some suspicions in my mind.