This statement just in from TBS:
TBS has reached the difficult decision not to order a third season of Lopez Tonight. Thursday will be the final episode of the show. We are proud to have partnered with George Lopez, who is an immensely talented comedian and entertainer. TBS has valued its partnership with George and appreciates all of his work on behalf of the network, both on and off the air.
The numbers just weren't there, particularly once Conan came to TBS and Lopez Tonight moved to midnight. Even in originals the ratings for Lopez Tonight have been anemic with the show averaging around a 0.2 rating with adults 18-49 and 400,000 viewers for originals.