It didn't take long. After Jack Warner announced CONCACAF have petitioned FIFA for 4 places (up from 3.5 they had for the 2010 World Cup), CONMEBOL announced they are determined to keep their 4.5 spots.
Interesting to see CAF also want to keep 6 spots for the 2014 finals. That's something I haven't heard before.
As you can see, Blatter was right when he said CONCACAF's bid for a fourth spot will be a struggle.