New faster Canon TS-E 24mm??

Rumours are there will be a new Canon lens out in the next couple of weeks - a replacement of the TS-E 24mm f/3.5L, this time faster at f/2.8.  Never used a tilt and shift lens myself, so can't really comment!

For me, I'd be more interested in them replacing the 100-400mm f/4.5-5.6 IS L with better IS and zoom mechanism (and slightly faster, but not heavier!?)... or bringing out a replacement to the 400mm F/5.6 L, with image stabilisation.