Conclusion
The end of single-core desktop processors is in sight. By 2006, most new desktop systems will use dual-core processors, and software will be rewritten to take full advantage of the multithreading advantages inherent in dual-core designs. However, you don't need to wait for new software to enjoy the benefits of dual-core processors. If you multitask heavily or create content with leading applications, you will see major improvements in performance and responsiveness with current software.
For Further Research
Intel Pentium Extreme Edition and Pentium D
Intel's official website for the Pentium Extreme Edition is located at http://developer.intel.com/products/processor/pentiumXE/index.htm
Anandtech's two-part review of the Pentium Extreme Edition and Pentium D is located at http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2388
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2389
Tom's Hardware examination of the Pentium D and Pentium Extreme Edition is located at http://www.tomshardware.com/cpu/20050405/index.html
AMD Athlon 64 X2
AMD's official FAQ page is located at http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_12898,00.html
X-bit labs review is located at http://www.xbitlabs.com/articles/cpu/display/athlon64-x2.html
Tom's Hardware preview is located at http://www.tomshardware.com/cpu/20050509/
Anandtech's review is located at http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2410
Intel 955x and nVIDIA nForce4 SLI Intel Edition Chipsets
Anandtech head to head review of both chipsets is located at http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2394
X-bit labs's review of the NVDIA nForce4 SLI Intel Edition chipset http://www.xbitlabs.com/articles/chipsets/display/nf4-intel_3.html
Tom's Hardware reviews the NVIDIA nForce4 SLI Intel Edition chipset at http://www7.tomshardware.com/motherboard/20050406/index.html