.com domains were intended to designate commercial entities:
http://en.wikipedia.org/wiki/.com
.tv is, as people have said, the country code for the nation of Tuvalu.
http://en.wikipedia.org/wiki/.tv
Anybody can register those domains. There's no particular connection between anything media/video and the country code for Tuvalu. However Tuvalu, being a tiny island nation with a population of less than 12,000 is making quite some money from people using their country code as a domain hack for TV channels or the like - the government receives more than $4 million in royalties per year...
Of course, the internet being the internet, there is no way of predicting where things might go in the future, and whether it would make more sense to register a .com or a .tv domain for any specific kind of purpose. I'd say that your guess is as good as anybody else's.
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Coat of Arms of Tuvalu:
Map of Tuvalu:
People of Tuvalu: