git-annex info when run with a path displays "repositories containing these files"
with a list of repositories and sizes. It would be good for it, when not
run with a path to display a corresponding "annex size of repositories".
I think that this recently became possible to inplement cheaply. cachedAllRepoData is collected now, used for "combined annex size of all repositories". For this, it also needs to accumulate the size of each separate repository. --Joey