System X started as 1,100 power mac g5's linked together. It was later upgraded to Xserve g5 servers. Since it's creation it has consistently landed high up on the top 500 supercomputers list and is hailed as a super cheap supercomputer (pun not intended) for its price and power(it cost 'only' $400 million)

I was just wondering,
1)If they upgraded to the new intel mac pro's would they see a huge performance increase?
2)can a home user network 3 or 4 (or any small amount) mac pro's and create their own tiny "supercomputer"?