Given the way Canon has "crippled" the 100D down to "entry-level" specifications, I do not think we can expect any EF-S primes. Canon should have brought these primes out years ago, basically as soon as they went with APS-C - in order to replace the 50mm f/1.8 as a "first prime" for budding photographers. They didn't, as they reason that that part of the market only wants zoom lenses (although the "higher" demographic is also primarily into zooms ... 16-35mm, 24-70mm, 24-105mm, 70-200mm, 100-400mm, etc.)
Canon has, in my opinion, created a bit of a problem for themselves with the 100D. It is definitely a camera with the sole purpose of preventing current "users" not to buy m4/3, as once you go there it's lost business for Canon. Yet, bringing out EF-S primes will keep people, as they grow photographically, in the APS-C segment. This bites into their "full-frame" business, with its inflated price tag, as "full-frame" basically loses a lot of its appeal - because you get the same from EF-S (and currently from m4/3).
Canon sees APS-C as (1) a method of selling cheap DSLR's to the masses, and (b) an "upgrade path" towards their expensive "full-frame" offerings. The new 100D makes it obvious that they are losing serious ground on point (1) to m4/3 and other "mirrorless" systems. Yet if they make EF-S a serious form-factor with dedicated primes and decent tele-photo lenses, then they lose on point (2).
Canon, just like Pentax, has not kept up with their market.