error: Failed dependencies:
libQtCore.so.4 is needed by VirtualBox-4.1-4.1.20_80170_el6-1.i686
libQtGui.so.4 is needed by VirtualBox-4.1-4.1.20_80170_el6-1.i686
libQtNetwork.so.4 is needed by VirtualBox-4.1-4.1.20_80170_el6-1.i686
libQtOpenGL.so.4 is needed by VirtualBox-4.1-4.1.20_80170_el6-1.i686
libSDL-1.2.so.0 is needed by VirtualBox-4.1-4.1.20_80170_el6-1.i686
yum localinstall VirtualBox-4.1-4.1.20_80170_el6-1.i686.rpm
yum localinstall命令就可以让yum去解决依赖性问题