The global movement to tax billionaires, much to the dismay of the 1%, is gaining steam. Sure, wealth taxes are not a panacea for the ruinous problems caused by capitalism, but the fact that the rich hate them is a good reason to pursue them further.
Actually, fleeing to tax havens tends to be less of an issue for some nations. For instance studies and polling have found that the US would have to raise the top income tax bracket to something around 90% before you would loose more in people renouncing their citizenship than the government gained in the increase.
Corporate tax rate on the other hand is a whole lot more competitive, especially in places like the EU where import restrictions and terrifs are low or non existent.