I funded my btc wallet and started the process yesterday night, I was able to initially connect to Dropbox and have the profile file for my account be pushed to my Dropbox connection.
Then there was a prompt for a brower update and after the update I am unable to choose anything other than the default storage.
We had to temporarily disable Dropbox support over the course of the token sale. By default, your profile will still be replicated to your local disk and to a bucket on Azure. We plan to re-activate it soon afterwards
The ID registration is separate from profile storage, however. You should be able to proceed as usual to set up your profile and add a Blockstack ID to your ID address without storage.