What is the difference between the following two processors and what are they (more) suitable for?
Intel® Core™ 2 Duo E6750-processor (2,66 GHz, 1333 MHz, 4 MB cache)
Intel® Viiv™-teknik - Intel® Core™ 2 Duo E6750-processor (2,66 GHz)
Basically, I believe those to be 2 different listings for the same processor. Read the link below. Clicking on the links to the right of the page takes you to the same listings as you will get from the Core2 Duo page without the Viiv listing.
http://www.intel.com/products/viiv/description.htm
An Intel® Core™ 2 Duo by any name is still an Intel® Core™ 2 Duo. 
;D