Or, wait and see if the T4i is really better in a significant way. If so, great, buy it.
If there are no meaningful changes, or if the changes are something you don't really care about, then you could buy T3i on a clearance sale. Apply savings to a lens.
Seems I saw someone speculating that the improvements would just be tweeks to the video function, which to me at least would not be a big deal. Of course that may be wrong, wrong, wrong.