In my defense, I never really saw the value in any glass that was crop frame specific.
I only use Nikon DX lenses(*) because when I bought the D5100, I didnt wanted to be set in my choice of Nikon just yet.
And sure enough Fuji is making some very tempting offers recently. With the new X100s, they even introduced Phase AF on their sensor. Maybe soon I can have a camera that is half as heavy, with excellent optics, and still can manage action and sports well enough - well as long as there is enough light.
Also, the Nikon DX stuff is cheaper(**), smaller, more lightweight and not that bad, optically.
Also, I was new to DSLRs and didnt knew exactly what I really wanted, yet.
(*) If any reader doesnt know: Nikon DX ~ Canon EF-S, except Canon is 1.6 crop and Nikon is 1.5 crop.
(**) Except for the 50mm f1.8, which curiously is even a bit cheaper than the 35mm f1.8 DX.
Dao - I'm in the "going full frame at some point" camp, where (to me) buying crop frame lenses means I'd be throwing money away.
You can always just sell your old lenses.
Also, with full frame you need new lenses anyway, since the old ones mean entirely different things now.