Videos will initially appear alongside photos in a business listing and will be limited to 12 seconds so you'll still want to include the bulk of your review in the text. While their roll-out plans are to start with their "elite" users, we should all start seeing video reviews appear sometime in June.
In my opinion, this new feature has the opportunity to be a game-changer for local businesses. With the increasing importance of online reputation management, videos will add credibility and a higher level of trust in the reviews. And, in the case of the irrational 'hater' reviewers - videos have the potential to empower them to discredit themselves.
I am already talking with restaurateurs and local business owners about ways to solicit video reviews from their happy customers in order to amp up the power of this new opportunity. It's definitely worth some forethought to determine how you can best capitalize on this as well!