My vimrc has a specific section just for handling this:

    """""""""""" DVORAK FTW LOLZ! "
    noremap d h
    noremap h j
    noremap t k
    noremap n l
    noremap k d
    noremap l n
    noremap j t
    noremap ^Wd ^Wh
    noremap ^Wh ^Wj
    noremap ^Wt ^Wk
    noremap ^Wn ^Wl
    inoremap ^] ^[A
    inoremap ð ^N

That's all I use for handling dvorak. This has been in my config since I switched to git from hg in 2007, dunno how long before that.