Don't you mean the other way around? Mine was out years before theirs. They should have googled the words "async.js" (which my lib was the top result for prior to caolan's repo) before naming their project.
Years? Really? Not to nit, but the only way "years" is accurate here is if you mean "0.3 years".
Your first commit was that January and Caolan's was that May, and when yours was "out" is debatable anyway since you don't have any releases tagged.
I would hardly feel obligated to rename a project over a 4-month-old Github repository that doesn't even target the same platform (Firefox vs. async being originally Node-only).
Sephr's eligrey/async.js predates (01/2010) the lib you mention, caolan/async (05/2010), at least git history–wise, although the latter looks actively developed.
Edit: it appears that the caolan async lib came out after yours. Sorry for the confusion.