1) Show only the current day and future days -- Google Calendar does this
2) Can't see when other people are busy or free -- Google Calendar does this (if that person has shared their calendar)
3) Can't see when a group of people have common free time -- Google Calendar does this
4) Get an autoresponse if you invite someone when they are not free -- this is mooted by 2) and 3)
5) Jointed owned calendars -- Google Calendar does this (can give people edit permissions on your calendars)
6) Autoreject invites based on time -- Google Calendar does this
7) Location aware -- OK, gCal doesn't do this.
As we all know this comes down to money, who wants to pay $50 for a good calendar app? I know I would...
Irony? Or makes perfect sense.