Drive actually replaces Docs and adds a couple of new functions, the most important of which is a desktop client which is very similar to Dropbox. Storage capacity aside (most users probably don’t need more than 2GB at present), Drive has the big advantage that it also provides previewing (some 30 document, archive, image and video formats) and editing (Docs). Links to shared files and folders are opened in the mobile App, which allows you to edit files and make them available for offline use. These features actually allow you to replace Dropbox + Evernote (storage + note taking) with Google Drive.
Drive will definitely be my preferred service for collaboration in school, as I am already using Docs and most students already have a Google account (users of Gmail, Android, YouTube). That makes it easier to use in collaborative projects than Dropbox. Drive also allows anonymous collaboration (you have to be logged in, though), which further facilitates quick collaboration and has a great potential for mobile learning (quick and easy upload of notes, photos, podcasts, etc. from mobile phones).
I also use two Chrome plug-ins for Drive which allow me to instantly save attachments from emails and photos and downloads (cloudsave) from the web to Drive, respectively.
Here is a list of thing you can do with Drive:
- Access all files from the desktop and mobile devices
- Share files and folders via eMail and social networks, circles (on G+)
- Collaborate on files and folders
- Search for files and information - even in images (OCR)
- Save files from Gmail and the web to Drive instantly (Chrome plug-ins)
- Save documents for offline use (particularly useful on mobile devices without 3G)
- Insert files from Drive into Docs (e.g. presentations)
update: Google Keep has arrived and it is often compared to Evernote. Actually, Google Keep is mostly for quick note taking. For more systematic note-taking Google Drive is far superior. Still, Keep fills a void in that it has a thin and fast client with automatic syncing. Moreover it supports voice memos and Google Now integration (note to self). It is therefore a welcome addition to Drive and it can be hoped that it will be better integrated in Drive than it is now.