[font color=\'#000000\'](Your combination of forensic and now landscape reminds me of
another photographer.)
Canon seems to have a history of innovations with Nikon playing catch-up, but as mentioned Canon's lead in autofocus and now image stabilization earned them a large chunk of the market in sports and wildlife. But pure landscape tends toward a different equipment bias than either the action features in Canon's bag of tricks or the frequent close-ups you may be accustomed to with Nikons.
In order to choose the right equipment you first need to establish the type(s) of output you want to focus on. Slide projection, large prints, smaller prints, and on-line are all valid options but each favours a different type of camera.
Then you need to make a choice between digital capture and film capture. Then, if you intend to do prints, between digital darkroom and wet darkroom.
I suggest you stick with your current kit for at least the first few months of doing landscape. 35mm is a perfectly valid choice for landscapes, unless you have opted to do prints larger than roughly 11x16. You might pick up a copy of
John Shaw's Landscape Photography. (Incidentally, this guy has long made a living at landscape photography with Nikons, so sticking with your current brand is not an unreasonable option.) Even though aimed at the beginner, this book does a good job of giving a feel for the type of equipment decisions you'll need to make.
Finally, another great resource is the
Nikon MF forum. Anyone who has been shooting Nikon since the F will feel right at home with these guys.
I happen to shoot Nikon too. An F2 and an F80 with the 35-70/f2.8 attached, Reala film, and digital darkroom gets me scads of colour prints up to 12x18 that are perfect for covering the cracks on my walls.[/font]