These L lenses were introduced before 2006 and are still in production. They are likely to get a Series II or IS update.

1993 EF 400mm f/5.6L USM
1995 EF 70-200mm f/2.8L 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
1999 EF 70-200mm f/4L USM
2004 EF 28-300mm f/3.5-5.6L IS USM