It looks like Sony pulled the plug on the very popular Uncharted 3: Drakes Deception Beta, but Sony also released some statistics from the beta's run. Most of them are pretty impressive.
First of all, Sony is calling this beta the "largest PS3 Beta ever". The stats they include in their announcement back up the statement. Over 1.5 Million people participated in the beta. 1.9 Billion kills. 48 Billion shots fired. 22 Million matches completed and with those 22 Million matches, 362 years of gameplay was put in this beta. So, it's safe to say that the beta was a success.
Why did the beta do so well? Was it the popularity of the game that influenced so many to play? Even though the game is one of the highest anticipated of 2011, the reason why the stats are so impressive is because of the free PlayStation Plus access. The Uncharted 3 was originally going to be for PlayStation Plus subscribers only, and it was. However, the Welcome Back program gave pretty much any user with an internet connection access to the Uncharted 3 beta with free month of PlayStation Plus. The beta would've done well regardless, but the jaw-dropping numbers are from the wide variety of people that could participate.