As a long time employee of Land Rover North America I'm personally very optimistic of Jaguar and Land Rovers future. It will be good to be owned by a very successful company that will have the resources to allow Jaguar and Land Rover to develop new vehicles and technologies to remain competative. Tata has a history of not tearing companies apart and diluting the value of the brands they purchase. Tetley Tea and Corus Steel are two British Companies that they own and they have kept the management teams and employees in place.
Also the demise of MG Rover was due to the Phoenix corporation mismanagement after BMW gave them 10 pounds to take them off their hands. This was after Rover Group sucked billions of dollars out of BMW. They continued to hemorage money while British management of Phoenix stripped it bare. For more history of the downfall of MG/Rover see here:
http://findarticles.com/p/articles/mi_qn4158/is_20050409/ai_n13596420 
