The trouble is that before long there'll be another study showing that acupuncture is not any good for treating back pain.
Acupuncture can't be done double-blind so there's always the chance, or rather likelihood, that experimenter effects will affect the outcome of any trial.
There's no real strong evidence to back up that acupuncture works for anything and, personally, I view any form of 'therapy' where the results are 'suggestive' rather than definite as being a one that doesn't really work. If acupuncture really did anything, we'd know about it by now.
Or, alternatively, if it does do something then it isn't much! So, is there any point in pursuing a therapy if its effect size is so small that it's practically indiscernible?
There was a trial done a few years ago which showed that acupuncture was efficacious in treating knee osteoarthritis and this example is often used by proponents as 'proof'.
A recent study has shown just the opposite however: http://dcscience.net/?p=45
So what are we seeing? Is it that some trials are accurately picking up the small but real effects of acupuncture or are these positive findings just spikes in the noise?
Either way, I really don't think there's much to shout about. Even if it does work, e.g. for pain relief, it's effect is only about as much as taking a couple of aspirin.