The problems on Commons are a direct result of the enourmous growth in Commons. Currently the counter is at 3.5M and that number is increasing with 120K each month. Last time I checked (about a year ago) about 10% to 20% of those images is deleted. If this value is still the same, which I expect, then an unhealthy total of 20K images per month are deleted.
A significant amount of the deletions could be avoided if every user was helped personally in fixing the images. I'd wish every image could go through a community review but with the amount of images this is simply not possible. The backlog for regular deletion requests reaches to 11 Feburary 2008. 10 months, and I have seen it slowly increase: 6 months ago the backlog reached to 30 December 2007, a backlog of 6 months. The backlog has thus increased by 4 months in 6 months. If this trend continues we will have a backlog of one and a half year in one year.
The problem is not specifically the lack of admins, but the lack of community. Many deletion requests could use community input. Many new users could use an experienced member guiding them through Commons and help them fix their mistakes.
Unfortunately I see no solution (except, say, disabling uploads for the coming month ;))
Bryan