The article is correct - it's all about the rice. This is why I don't like sushi sold in supermarkets - it has cold rice, but at a sushi bar you get this nice warm sweetened rice that makes all the difference.
The rice-making is easy, and far from mysterious. You need good short-grain white rice (you can use brown rice, of course, but it’s not the same thing), rice vinegar, sugar, salt and kelp (or konbu, a kind of seaweed). Some sake is nice, but it is not essential. You blend the vinegar, sugar, salt and kelp, remove the kelp, then let the sweetened vinegar (now called awasezu) sit at room temperature or in the refrigerator for as long as you like. (I haven’t tested to see how long it will last, but several days are certainly fine.)
You cook the rice, adding a little sake to the water if you have it; the proportions are about one-and-a-half parts water to one part rice, though you can get away with less water if you have a rice cooker.
When the rice is done, you let it sit for 15 minutes or so, then you fold in about a half-cup of awasezu for every two cups of cooked rice. You do this gently, so as not to crush the rice, but it’s not as painstaking a process as it’s sometimes made out to be.
If your goal is to become a great sushi chef, you can take this more seriously. But for me, it seemed the rough equivalent of folding egg whites into a batter. The rice will absorb more awasezu than it needs, so you have to keep tasting and stop when you have the right, slightly sweet-and-sour flavor.
http://www.nytimes.com/2010/05/05/dining/05mini.html