If you are not going to be playing any games then just about any laptop with a Core i3 will suit your needs. The following Lenovo IdeaPad Z570 for $500 should suit your basic needs.http://www.newegg.com/Product/Product.aspx?Item=N82E16834246314
While the Core i3-2350 @ 2.3GHz is 100MHz slower than your Core 2 Duo mobile CPU, the actual increase in performance is about 20% thanks to a better CPU architecture.
Click the following link which compares the desktop Core 2 Duo E8600 (3.16GHz) and the Core i3-2100 CPUs (3.1GHz). Mobile CPUs are based on the same architecture as the desktop versions so the performance should more or less correlate to each other.http://www.anandtech.com/bench/Product/55?vs=289
Ignore the SYSMark 2007 synthetic benchmarks. Synthetic benchmarks are basically crap, because actual benchmarks paints a difference performance picture.