Yes, the more power produced, but don't confuse that for more power as in more speed to the video card or system. Having a more powerful power supply does not mean any components will run faster than they would with a lower power PSU. There were people that thought exactly that.
Unless you are going to be running dual video cards or a very high end video card and overclocking your card and CPU, you don't need to go over 600 watts. If you are looking for a lower end gaming card like the 7770, you are fine even with a 450-500 watt PSU.