I've been meaning to catalog the various security surveys and reports produced by vendors. However a recent thread on securitymetrics.org beat me to it. Various members of the mailing list contributed to the below. I hope it's not rude to just include the links since I didn't do the leg work...? Let me know if this offends anyone and I'll remove it. Note a couple require registration and, aside from confirming the hyperlink, I haven't read all of them.
Throw in the analyst's work and the sheer number of reports is impressive. Pretty soon we'll have a report on the reports!