Just got news that the latest Canon 40mm F/2.8 STM lens will start shipping this Friday. For T4i owners, this STM lens is designed specifically for the Auto Focus feature of the T4i to be quiet and fast.
I did not opt in for any lenses when I purchased the Canon EOS T4i, but I should be this pancake lens next week to see how usable the Auto Focus is. I was testing out the Touch Screen focus feature on the T4i with my other L lenses, and it seems to be fairly accurate. This new 40mm is listed as an EF (not EF-S) so it should be a decent focal length for both Full Frame and APS-C cameras. Available for Pre-Order now.
Canon 40mm F/2.8 STM Lens