The Bottom Line
If you already use Dropbox you should probably stay with Dropbox unless the search function is important to you in Google Drive or you are a heavy user of other Google products such as gmail or Google+.
If you are new to cloud computing and want to store some documents online then Google Drive offers a compelling case. Drive can be quickly set up for anyone who already has a gmail account or is a user of the Google+ social network. At the moment, Drive works with Windows, Mac and Android phones. An iPad application is expected soon. So far, no word on when Drive will work on Linux.
The preferred alternative is to wait a month or two and see how the marketplace evolves. Placing personal information in the cloud is a long-term investment since there is a high cost to switching to another service.
Within a week of the launch of Drive, Dropbox introduced a new service to make it easier to share files and Microsoft dropped the price of its SkyDrive service. More changes/revisions will almost certainly occur into the summer of 2012 as the other various cloud services step up their offering to compete with Google.