http://people.centos.org/tru/devtools-2/readme 

2014/03/09: C6 i386 and C5 i386 and x86_64 added + devtoolset-2-binutils
2014/03/07: only the C6 x86_64 is built at this time (unsigned)

you probably want:
wget http://people.centos.org/tru/devtools-2/devtools-2.repo -O /etc/yum.repos.d/devtools-2.repo
yum install devtoolset-2-gcc devtoolset-2-binutils
yum install devtoolset-2-gcc-gfortran

known issue:
0) unsigned packages
1) CentOS-6 devtoolset-2 needs devtoolset-2-ide which contains the whole eclipse stack but does not build yet
2) CentOS-6 all the maven related file are not built either

main changes from devtools-1.1:
- /opt/centos is no longer used
- /opt/rh is now used as upstream (as SL version)