Finally figured out how to make bash delete words the same way Vim does. For starters I enable vi editing mode in readline. So, when i press Ctrl-W I expect bash to delete up to the previous word delimiter. By default bash/readline deletes up to the previous space. So, to enable the use of punctuation as a word delimiter while using vi editing mode one has to use the following in the ~/.inputrc

set editing-mode vi
set keymap vi
set bell-style none
$if mode=vi
    set keymap vi-command
    "gg": beginning-of-history
    "G": end-of-history

    set keymap vi-insert
    "\C-w": backward-kill-word
    "\C-p": history-search-backward

Since IPython respects readline, this will take effect in the IPython shell. :)