Cobizz, since I dont work for Dell I cant say for sure what your laptop will support but here are some facts. The chipset is the 965PM and you can see information on that chipset at http://ark.intel.com/products/chipsets/28116.
On that page is the support processors for that chipset. Now your Dell may not support all of them so be careful. Dell's site for this laptop http://support.dell.com/support/edocs/systems/xpsM1530/en/OM/specs.htm
says that it will support the Intel® Celeron® and Intel Core® 2 Duo's with 65nm and 45nm with these buses 533 MHz (Intel® Celeron®), 800/667 MHz (Intel Core 2 processor), and 800 MHz (Intel 45 nm Core 2 processor). So there does appear to be some room to upgrade on your laptop.
Intel Enthusiast Team