[18/4/06 update: For some reason, the ALA changed the title and URL for Retirement & Recruitment (2004): A Deeper Look on its website. I have put in the up-to-date information below. The change basically involves changing the year from 2004 to 2002. If you want to see how the Office for Research and Statistics page looked in April 2005, it's available in the Internet Archive]
I've written a short article in the June 2005 issue of InterALIA about this topic. InterALIA is the ALIA South Australian newsletter. One of the questions that I had when I wrote that was wanting to know how similar (or different) the experience of Australian librarians has been from that of American librarians on this particular issue. If only somebody could replicate, or at least do something along the lines of, that Holt & Strock research in Australia...
One other thing about this article. Since drafting it, I've become aware of some more recent research by Mary Jo Lynch at the ALA Office for Research & Statistics which are based on 2000 US census figures, instead of the 1990 census. The report is called Retirement & Recruitment (2002): A Deeper Look [link to pdf].
To summarize, Mary Jo Lynch says that the librarian shortage which was predicted in her widely quoted article ('Reaching 65: lots of librarians will be there soon', American libraries, March 2002) is still going to happen. Here are two interesting quotes:
The 1990-based analysis predicted a significant wave of retirement that would peak in the 2010 to 2014 period. Updating the forecast with 2000 Census data, as shown in Figures 1 and 2 predicts a similar retirement surge in the near future. The main difference is that retirements now appear to peak slightly later—between 2015 and 2019. In total, the ten-year period beginning in 2010 will see 45 percent of today’s librarians reach age 65. This surge of retirement represents the early-wave of baby boom librarians crossing the threshold of age 65.
The net influx of mid-career female librarians, and their later departure from the field, will do little to diminish the retirement surge looming in 2010. It has only served to delay it somewhat. The short-term supply of librarians appears to be bound up with the fate of baby-boom women, while the longer-term health of the field depends on those who follow them.
It is interesting that even the true believers in the library shortage admit that it has been delayed somewhat. Other than that, this most recent update doesn't change the views which I've expressed in the InterALIA article and elsewhere.