It's important to not confuse that the QC option is $2K more. The $2K more between SL and SV includes more than just the QC option. The QC option is only $700 in the 2011 model.
Now why would you want to pay $700 for the QC option? First of all, it's not something you can add on afterward. So if you don't choose it up front, you won't be able to do any kind of QC at all afterward (at least for cheap).
And even if CHAdeMO is not going to be the standard (but maybe it will, we just don't know yet), as long as the QC port is there, people can make adapters to convert from whatever the standard is going to be to the CHAdeMO port for QC. Or maybe there will be third party options to swap out the current L2 port for the "new standard" port in its place, with behind-the-scene/under-the-hood rewiring to enable both DC and AC connectivity to the Leaf battery and charger. The CHAdeMO port can be left alone as is for CHAdeMO charge stations. Then you have the best of everything. As long as the QC heavy-duty wiring is already in place in the first place, it should be easier and cheaper to retrofit to a new standard. But if the wiring is not in place because you didn't pay for the QC option, it's probably not going to be easy or cheap to add on. Anyway, the bottom line is that the real issue is not about whether CHAdeMO is going to be a standard or not. The real issue is whether your car is equipped for QC wiring already or not.
Even if you don't need QC now, QC is going to increase the flexibility of your range. That makes it better for the resale value for your car. It also solves the range problem, not just from the standpoint of actual range needed, but it solves the problem of gradual reduced range as the car's battery ages. For example, let's say 5 years from now, your battery capacity is reduced to 70% of its original capacity. Without the QC option, you're limited to driving your car on much shorter trips than before, therefore, the resale value of your car plummets to nothing. But if QC stations becomes ubiquitous, and your car has QC option, people won't care too much if your battery has 70% reduced capacity, because the car still remains useful as long as QC stations are everywhere for them to plug in.
Some may argue that L2 public stations are good enough and QC is not needed. Well, it makes a big difference if you're using L2 on a 6.6kw charger as opposed to using L2 on the currently limited 3.3kw charger. Twice as much difference. So maybe you won't need QC as much if you have a 6.6KW on-board charger. But if you only have a 3.3kw on-board charger like we have now, it makes the QC option look a lot more attractive because your other main charging option is already a pretty lame 3.3kw. It may not look lame now, but when 6.6kw or 7.2kw or 9.6 kw chargers come out, 3.3kw will look pretty lame. But if your car is equipped with QC on top of 3.3kw, the focus/selling point is going to be on the QC, then all of a sudden it's not so lame anymore.
For all the reasons above, the $700 for the QC option sounds pretty good, even if you don't plan to sell your Leaf any time soon. Even if it allows you to make good use of your Leaf for a couple of extra years down the road before you have to upgrade to something better, those couple of extra years of use is definitely worth the $700 investment today.
To many people, the real sustainability of EVs is not so much in what range their batteries can deliver, but more importantly, how prolific public charging stations will become. And to follow up on that, how quickly charging can take place. If there are enough public charging stations around, and especially enough QC public charging stations around, you don't even need a 100 or 200 mile range battery. A 50 mile range battery may even be adequate if you can replenish it in 15 minutes when you make a stop.
The fact that 95% of buyers opted for the QC option on their Leaf is testament to their buy-in of this vision.
I would use the following analogy. Maybe not the best, but I think it brings the message across. Years ago, it seems like having a computer to do things is good enough, even without any connection. Then dial-up modem connection is desired to have on the computer to connect for email and websites. Nowaday, nobody would want to buy a computer without an Ethernet (and wifi) connection. Of course, the analogy here is the computer is your car. The modem connection is your L2. The Ethernet connection is your QC.