I'm at home with vim (10+ years + a finely tuned and pimped up ~/.vim/) and have used vimoutliner a lot, but it goes in the opposite way for me: org-mode is one of the reasons I'm considering giving emacs another chance :)
I disagree, Viper mode is a very thin imitation of a few Vim commands. Slightly too thin for my liking, even on the most compatible of modes :p
Besides, to really experience the benefits of Emacs you have to dive right in. There are many Emacs features I wish Vim had but I fear many of these diminish in value when taken out of their natural environment. The reverse can also be argued to a lesser extent.