A dual pixel AF Rebel seems the most obvious next step and quite normal in that whole trickle down thing.
This seems like the most obvious step, and would represent the biggest improvement to the line since the T2i/T3i. It would be tempting to get one, but I'm betting the camera range will be getting a big shake up over the next few years. Trickle down for 20MP (ish) sensors was: 1DsMkIII, 5DmkII, and then the 7D, then the T2i/60D, with the first two steps being roughly a year apart.
So the next round should be 1Dxs in 2014, 5DMkIV in 2015, and then something in the APS-C range with the same resolution in 2016.
I'm guessing the 7DMkII will be the "1Dx" equivalent in the APS-C line with other models getting a resolution increase long before a 7DMkIII is ever conceived. By 2020 computers should be fast enough for sports photographers to be willing to work with more resolution (and maybe the introduction of 8K displays will help push cameras further, our 20MP pictures today will look like crap 10 years from now, heck even on my 4MP display many 5DMkII pictures start showing their weaknesses).
The big question for me will be between the 1Dxs and 5DMkIV, I really like the large style body, but the extra $3K-$4K would go a long way toward a big white (800f5.6MkII can't come soon enough).