Welcome to the forums.
Your video card and Ram is decent enough to run the game on medium/medium-him settings
Your entry level dual code CPU will work as well - however - I`m almost sure you will get major lag in very large scale combat. We are reworking our pathfinding system - and with-in a month your Dual core will be able to handle the large scale combat pretty well.
Meanwhile - game will run fine - until you get into medium-large scale PvP and stay away from Castle Defend type of gameplay.