If you tried accessing your Google Drive, but it says that it is not ready yet, there is a little workaround I just discovered.
Follow these 2 steps:
(1) Go to the Google Play Store on your Android Device and download the app.
It will automatically log you in, and again give you the same screen stating that your google Drive is not ready yet.
(2) Switch screens internally in the app (meaning, switch to another account if you have more than one, or go into the settings of the app, or whatever) and then press the back button to go back to the main Drive screen. Exiting and reentering the app may work as well, but I don't know because I haven't tried that.
You will notice that once you go back to the app, the message is gone and you have full access to your Google Drive on your Android Device.
**It only gives you access on your phone though, website Google Drive will still not work until its ready**
PS - Please don't comment things like "why not just wait" or some derivative of that. If you would like to wait, that's great, keep that to yourself. This is for those that don't want to wait. Thanks for understanding.
Just found out btw, that you can also just upload directly to Google Docs (any file format), because Google Docs and Drive are going to be Merged and already reflects your 5GB storage amount.
Edit 2 -
Here is the desktop application for all those asking