Original sentence: Based on statements made by Sun's executives, Sun's major focus at present seems to be utility computing, a system where people can buy time on Sun's computers for a dollar charged per cpu used per hour, and a dollar charged for gigabyte of hardrive space used per month
Edited sentence: Based on statements made by Sun's executives, Sun's major focus at present seems to be utility computing, essentially a rehash of the mainframe  time-sharing system where people can buy time on Sun's computers for a dollar charged per cpu used per hour, and a dollar charged for gigabyte of hardrive space used per month.In the last three years, under the leadership of CEO Jonathan Schwartz, the company's market capitalization has dwindled by over 90% to approximately $13 billion as of this writing