The chess world has a new No.1 player, Magnus Carlsen of Norway, and he is only 18 years old – the youngest No.1 ever. On Saturday, Carlsen beat No.11 Peter Leko of Hungary in the final round of a tournament in Moscow. Although Carlsen only tied for second in the tournament, it was enough for him to edge out Veselin Topalov of Bulgaria for the top world ranking. Topalov, 34, did not compete.
Carlsen is only the seventh No.1-ranked player since the ranking system began in 1970. Garry Kasparov, the Russian former world champion, became No.1 in January 1984, when he was 20 years and nine months old. He held it for 18 months, lost it, and then regained it and held it for 20 consecutive years before retiring in 2005.
Source: http://www.smh.com.au

The journalist does not seem to know the difference between official FIDE rating and this live rating. Magnus is NOT the highest rated yet. I think, as the situation is now, that highest rated not proves that you are the best either. There are not many rating points that differ the top players. ELO is not a perfect science. Seriously, Magnus would not beat Anand or Kramnik in a ten rounds match. But he will be the best, for sure.
Also Kramnik has never been sole #1. So even if Magnus maintains his ratings, he will be the sixth sole #1.