I assume you are a developer and have access to apple's developer forums.
There is a direct link in those forums from which you can download the DP2 delta update in a browser instead of the mac app store.
Other developers are having similar problems and this direct link solves the problem.
We can't post the link here on macrumors though.
I did not find the delta update link in the forums. Will you please give an idea how to go to that link if not the actual link?