Probably. Although I rarely have trouble understanding Indians, English is one of their official languages, and most speak it. They just speak it with a heavy, and unusual, accent. Their grammar is just fine. I'm of course speaking of the educated Indians, but those are the ones that they hire for tech support.
However one way that companies could handle the situation is to have an 800 tech support number that connects you to India or wherever, and a 900 number for US based tech support. They'd find out real quick if people are willing to pay more for US tech support.
If I were running Dell — I’d adopt the Jet Blue model of phone support. There is no tech center. The employees field the calls from their homes through a special line. That brings the costs down somewhat.