Keep on your hard work. I like this much more than my Webcalendar interface!
What I would need to deprecate Webcalender plugin is:
(*) Import/Export (iCal)
(*) Event reminders (Cron Job)
(*) Implementation of Google Calendar API (not supported by Webcalendar but on my - now stopped - ToDo's)
(*) MiniCal (to implement at bottom of folder list)
Just my 5 cents