HP System Bundle, Quad-Core 2.3GHz, 8GB/640GB, 20" LCD Monitor for $549.99 shipped after a $150 rebate and a $50 rebate.  Here is a screenshot for your reference.  It comes with AMD Phenom X4 Quad-Core CPU at 2.3GHz, 8GB RAM, 640GB drive, DVD burner, Ethernet, USB, Firewire, GeForce 9100, and more.  This bundle also comes with a HP 20" LCD monitor.

Originally posted earlier, this is just a friendly reminder as this deal is expiring soon.