crobb305 - 1:01 am on Mar 31, 2011 (gmt 0)
I doubt Google would downgrade a site for having a site to .gov.
I have been considering the possibility that G would downgrade a site for linking to the same source too frequently or, perhaps, to .gov (or the same family of .gov pages) too frequently. My site has tended to do this and following my hunch, I have cut down on some of these.
Also, I am considering the possibility that placement of outbound links on the page (particularly if they are followable) could play a role. I tend to create a "Resources" section at the bottom of my pages, with some useful outbound links. I have started interspersing links throughout the body text a little more.