I do hope it's the year of the lens (My wallet however disagrees...)
35 f/1.4L III would be interested as I do not have a current 35mm. However, everyone reports the existing one as being very good. Appart from weather resistance and the use of newer coatings Canon could improve the edge and corner performance (according to photozone.de). I have seen rumors about this lens since 2008 though...
Now that price comments...
EF 100-400 f/4-5.6L ISIt has been discussed before. Nothing to add. I agree of course, although I have a fine current 100-400 that I will keep.
EF300 f/4L ISActually it has to be 300 f/4L IS II. There is already an IS version.
This is very welcome considering the need to have a top quality weather resistant lens with IS. It is reported that the non-IS version has better optical quality than the current IS version (Just like 70-200 f/2.8L vs. the 1st version 70-200 f/2.8L IS). I do not have an opinion of the IS version but I am crazy about my non-IS 300mm L lens.
EF400 f/4L ISActually I was hoping for an update of the 400 f/4 DO lens. I realize though that in that case a possible second version -assuming that an improvement in optical quality is possible - would cost as much as the 500mm f/4L IS II (~10000 dollars, euros, whatever

)
So this (L version) will be more than welcome I guess.
Where is our 400mm f/5.6L IS though ? ? ?
EF135 f/1.8 ISIS would be a real gift. However I like my EF135 L lens so much that it would be difficult to upgrade considering the price. But still...