For an overview of the flurry at the time see this post by Edward as well as these two from Alpha.Sources. More generally you should also go see this aggregated blog of all Edward's posts on the Japanese economy. As you can see by following the links above the members of this team were somewhat sceptical about this sudden change of fortune for Japan and recently it seems as if the declining population and the subsequent demographic outlook for Japan has gotten due attention from some of the initial optimists (Economist article walled for non-subscribers).
(From the Economist)
"Early this month came news that Japan’s fertility rate (the average number of children a Japanese woman bears in her lifetime) fell last year to a record low of 1.25. It was, said the prime minister, Junichiro Koizumi, “an extremely tough figure”. Demographers had hoped that the fertility rate would bottom out at over 1.3, compared with a population replacement rate of 2.1, seen last in the early 1970s. Last year, too, the population saw its first decline in peacetime since records were kept. The government predicts that the Japanese population of nearly 128m will fall to just over 100m by the middle of the century. Nothing less than national survival, the Yomiuri Shimbun newspaper despairs, is at stake.
Some blame the demise of the traditional omiai, or match-maker: in the mid-1960s love matches overtook the number of arranged marriages for the first time, but now women want to get married later or not at all. Politicians, hitherto shy of sounding like wartime propagandists, are now urging women to breed. The government’s trade ministry even promotes the computer-dating industry. One of the biggest firms, Zwei, whose brochures are full of soft-focus idylls of white weddings, says its research shows most single people under 45 do not remain unmarried by choice. Rather, busy professionals simply haven’t found the right partner. Zwei and others are happy to help.
It is anyone’s guess when the fertility rate will turn up. For now, though, what matters is not so much a falling population but a change in its mix. Since the second world war, average life expectancy has jumped by 30 years, to 82. After the war, just 5% of Japan’s population were over 65. Today, the proportion of elderly, at 20%, is the highest in the world. By 2015, one in four of all Japanese, or 30m, will be over 65. Less remarked is a coming sharp decline in the number of younger workers: over the next decade, for instance, the number of Japanese in their 20s will fall by 3m, to 13m. It means that by 2030, there will be only two workers for every retired person, and three workers for every two retirees by mid-century. The Labour ministry estimates the workforce is shrinking by 0.7% each year."
Troublesome reading indeed.