It will still exist as a product for awhile though, so I think it warrants it place on the list even if I transitioned over to Todoist a few months ago.
I transitioned to Todoist as well. I really love its rich feature list.
Wunderlist hasn't given an exact date for when they are retiring the product but they have said it will be retired at some point. (Probably once the feature list of To-Do moves up to where Wunderlist is.)
The huge downside, IMHO, is that they decided to reinvent the wheel completely instead of using existing standard for file-format (icalendar?), sync(caldav), etc. :(