As a GSM Galaxy Nexus owner, the 16GB storage space is scarce and having this feature can potentially free up gigabytes of storage space. Video streaming works over both Wi-Fi & mobile networks (beware your data limit!) without a problem. Dropbox has always been a leader of consumer cloud storage services by providing highly useful features, no file size upload limit, a great user interface, and now video streaming. Note what I said earlier: this feature is only for users with devices running Android 4.0+ (ICS).
This also makes the Samsung Galaxy S lll even more attractive as every new owner will be given 50GB of Dropbox storage for two years, a nearly $200 value over the life of the bonus storage period.
Dropbox is available for free via the Google Play Store