I actually do more landscape photography with a 105mm lens than with my 28mm lens on my digital.
If you want good landscape pictures, it's actually easier to start with a longer lens than with a wider lens.
I also have a feeling that I'll be getting a Nex-5 as well. It will complement my 4x5 perfectly for longer trips, enabling me to have my cake and eat it, too. I'm also thinking about getting a TrekPod to go with the Nex (eventually... and maybe).
Hm. Maybe after I get a Nex I can sell my Nikon toys and switch entirely over to an Alpha setup to share the glass. I really only use the Nikon for portraits and events right now anyway, since it's almost as heavy as my Arca.