A lot of us are waiting for updates to the lenses below.
Pre-2006 L primes that are expected to be updated from oldest to newest
1993 EF 400mm f/5.6L USM
1996 EF 200mm f/2.8L II USM
1996 EF 180mm f/3.5L Macro USM
1996 EF 135mm f/2L USM
1997 EF 300mm f/4L IS USM
1998 EF 35mm f/1.4L USM
Pre-2005 L zooms that are expected to be updated from oldest to newest.
1995 EF 70-200mm f/2.8L USM
1998 EF 100-400mm f/4.5-5.6L IS USM
1999EF 70-200mm f/4L USM
2002 EF 24-70mm f/2.8L USM
2003 EF 17-40mm f/4L USM
2004 EF 28-300mm f/3.5-5.6L IS USM
As such we visit CR & NL for leads on what and when these products will pop out.
Now I have noticed for the past few years that Canon & Nikon tend to try to outdo each other by being each other's follower. If Nikon releases a 200-400mm VR Canon has to respond with the 200-400mm IS with an added twist being the Ext 1.4x.
Seldom do they introduce new products out of nowhere like say the 200-400mm VR, 14-24mm, 800mm IS, TS-E 17mm, 8-15mm Fisheye, etc.
So what Ls do I think will be updated or introduced within the next 24 months? The answer is below
1991 TS-E 45mm f/2.8 (2008 PC-E Micro NIKKOR 45mm f/2.8D ED)
1991 TS-E 90mm f/2.8 (2008 PC-E Micro NIKKOR 85mm f/2.8D)
1998 EF 35mm f/1.4L USM (2011 AF-S NIKKOR 35mm f/1.4G)
2002 EF 24-70mm f/2.8L USM (2007 AF-S NIKKOR 24-70mm f/2.8G ED)
2003 EF 17-40mm f/4L USM (2010AF-S NIKKOR 16-35mm f/4G ED VR)
2004 EF 28-300mm f/3.5-5.6L IS USM (2011 AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR)
I also expect an L treatment for the AF-S NIKKOR 14-24mm f/2.8G ED soon.
Did not include EFS lenses as they are not an area of interest.