text rotation and mathtext

Can text created with mathtext can be rotated? I am trying

    > to label a y axis like y = ylabel(r'$rm{Temperature}
    > (^\circ C)$') and y.set_rotation() does not respond to
    > 'horizontal' or 'vertical' settings.

Vertical rotation is not supported yet. I adjust the alignment args
so at least the horizontal ylabels are in the right place

  ylabel(r'$\Delta_{i+1}$', fontsize='x-large',
         verticalalignment='center',
         horizontalalignment='right',
         rotation='horizontal'
         )

The good news is that Jim Benson just sent me a patch to support
vertical mathtext in *Agg, which will be included in the next release.

Cheers,
JDH