We are indeed working on bringing this to IE as well, but we're waiting until at a later stage. Keep in mind that this is all still alpha code. As jeresig poin

We are indeed working on bringing this to IE as well, but we're waiting until at a later stage. Keep in mind that this is all still alpha code. As jeresig pointed out, Canvas is really only used for calculating click-through maps on objects which can be ignored / done server-side. It should be relatively easy to fix remaining bugs in IE.