Upcoming Zeiss releases for Canon Cameras over the next year
<li> 35/1.4 â€“ available from December</li>
<li>New version of the 25/2.8 (f-ratio suspect) â€“ available in May. ZE will be the first version released.</li>
<li>One lens shorter than 18mm â€“ perhaps a 15/4</li>
<li>Two lenses longer than 100 mm.</li>
A short, 15mm or less, lens would work very nicely on a crop camera - for Canon that would be 24mm. There are currently very few options at that focal length for APS-C and none that I'd call "professional grade".
Personally, I think I'd prefer a 13 or 14mm as that start to get into the truly wide angle for APS-C.