I have been living in Ho Chi Minh City for a month and the entire downtown area has been closed down on Sunday mornings due to the protests.
Anti-Chinese sentiment is quite strong and I have been treated to a few diatribes about the history of Vietnamese control over the Spratlys and Paracels before Chinese imperial conquest and historical revisionism. Lot of questions about why America hasn't gotten more involved in the dispute.
Vietnam, and to a lesser and different extent China, are experiencing various economic and social problems. In those circumstances dictatorships are bound to engage in cynical flag-waving to distract the population. But many dictatorships have been overthrown after such flag-waving goes wrong and the political elite obviously have to think of this as well.