No, if i were you, the minimal i would go with is at least a 650-watt PSU by a quality brand like Corsair or Antec, preferably 750-watts or greater.
My brother in law uses a corsair 650-watt PSU for his 460 SLI setup but if he decides to up the ante and get 2 x 570 for SLI, he will certainly need a better PSU.
My advice, if you have the cash to spend, ALWAYS get a decent PSU with room for upgrades. it will last for at least two rigs and leave room for upgrades.