The USGA has created a new rule to limit the backspin performance of grooves on lofted clubs. The rule downsizes groove volume and limits edge sharpness for all grooves manufactured after January 1, 2010 so they're equal to or less than the previously approved V-groove dimensions. PGA Tour players must use wedges conforming to the rule beginning 1/1/10. The ruling will decrease backspin and increase stopping distances pros typically achieve from grassy lies, and place more of a premium on hitting fairways.
How does the new rule affect you? If you're an amateur who wants more backspin, you realize the grooves you play determine the third factor in your backspin equation and the stopping distances you achieve on greens. In this regard the USGA has been lenient. The rule gives amateurs (who don't play in Major/USGA events) a choice of which grooves to play until at least 2024. If you want to maximize your short-game backspin, you can legally play with box or U-groove wedges (manufactured prior to 1/1/10) until 2024, or maybe forever. On the other hand, if you play with any wedge manufactured after 1/1/10 (like the pros will be doing), it must have grooves with spin performance at or below V-groove levels. This will limit you to mediocre spin performance. The USGA leaves this groove choice up to you.