I received a roadmap of sorts recently. The information went on to describe what's going on with a few of the new lenses supposedly coming from Canon, as well as some camera body information.
135 f/2L II
There is a replacement in development, and a prototype exists. However, it is not slated for release for a year or two. The current 135L sells well, and is very high performance.
35 f/1.4L II
The prototype exists and is slated for a 2011 announcement.
24-70 f/2.8L II
Apparently 5 versions of this lens exist. A few even have IS. It is slated for a 2011 announcement. The patent we've seen says no IS.
300 f/4L IS II
Expect this lens to arrive sometime in 2011 or early 2012. If what is mentioned next is true, then f/4 lenses may become more in demand as photographers aim to carry a lighter camera bag.
APS-H & ISO
The 1.3 crop will be going away. All cameras going forward will be APS-C and full frame. The ISO performance of upcoming cameras from Canon will be industry leading. This is in part because of sensor technology advancements as well as DIGIC V.
All of this is pretty plausible. I do expect Canon to have a couple of surprises up their sleeves. We've seen that recently with the zoom fisheye and the 200-400 with the 1.4 teleconverter built in.