I ask people on the street about this, and while most of them say that they think Malvinas are Argentina (and I would agree, really - look at the map), I have not met one that thinks they are worth having a war about.
Most have said that the Brits really don´t have a leg to stand on with their claims (at the same time, they are not interested in arguing about it), but don´t hold a dim view of Brits personally. I think they are smart enough to know (from their own experience) that you can´t judge a people by the actions of their government.