Reasons
1) Nikon's AF-S NIKKOR 35mm f/1.4G announced last September.
2) Carl Zeiss' Distagon T* 35mm f/1.4 announced also last September.
3) Sigma 30mm F1.4 EX DC HSM (though this is probably a stretch)
4) Canon marketed the 35mm back in December 1998.
5) Back in 1999 marketed 10 lenses. In 2010 they announced 5 lenses. This would have a leeway of 5 or so lenses for Canon to ship this year. This is a genuine stretch but who knows.
What improves can be brought to the flawless lens? Plenty!