I think that's an interesting concern, but you might be in a different enviornment than I am.
If "network dependence" is an issue for you, you could check in your ~/.m2 directory iff you don't want to run a repository server and you're deploying to many machines that have access to source control (which you probably do if you're running maven on that machine) and you don't have access to the internet. Then it's almost like a Ant 'lib' directory type of build, but with version information, docs, and sources all available if you want it and easily refreshed when you do have network access.
If "network dependence" is an issue for you, you could check in your ~/.m2 directory iff you don't want to run a repository server and you're deploying to many machines that have access to source control (which you probably do if you're running maven on that machine) and you don't have access to the internet. Then it's almost like a Ant 'lib' directory type of build, but with version information, docs, and sources all available if you want it and easily refreshed when you do have network access.