One of the reasons that I have preferred Dropbox to other cloud services for so long is that you don't have to have an internet connection to access your files. Also, Dropbox syncs automatically so there's no risk that something you saved won't be there.
Now that Google has released this program, that concern is no longer valid. In addition, my Gmail and Google Docs will automatically link up with Google Drive. This means that when I open an email attachment, it will go straight to Google Drive for later use. Brand recognition is going to be a big selling point for this program. People are using Google everything these days, so why not add one more piece to the puzzle. Apple has made millions with the idea of compatible devices and Google is doing the same.
Old habits die hard and I'm not quite ready to let go of Dropbox just yet, but I've already downloaded Google Drive to try out and the functionality is great. I would bet that I'll be moving everything over to Google sometime in the near future.
Here's another video discussing benefits of Dropbox versus Google Drive. Sounds like this guy might be making the switch as well.