(**Just heard back from my Microsoft Service Call Below that WP8 is supported with Office365)
As a very happy office365 user (that is where I host my primary email), I was very disappointed when I could not save appointments I schedule on my calendar. Knowing that I pay for enterprise level support, I posted a service request to the Microsoft Office365 web site describing my problem. The answer I got back, after much discussion was that very clearly that Office365 does not support windows phone 8. I’ve included that letter below if anyone questions my interpretation of what Microsoft support told me (Patrick’s spoken english was much better than his written english).
Hello Mr. Kellner,
My name is Patrick with Microsoft Online Services Technical Support.
It has been my pleasure to work with you on your service request # 1188400455. Based on the information provided the issue has been resolved and the Service Request will be archived as resolved.
You contacted us today in order to assist you with calendar sync issue you were having with your windows 8 phone. I indicated that we do not support Windows 8 phones, at the current time. I conducted a test on your android phone, & were successfully able to sync a calendar event from your mobile device to Outlook Web Apps. After we verified this there was no issue with the Adnroid, but with Windows 8, I asked for your permission to close the service request, which you denied. Again we do not support windows 8. So at the current time we can help with your current issue. Microsoft is working on getting things straightend out so that you can use yuor windows 8 phone in the same manner that you can currently use your Android phone.
Somewhat shocked by this, I tweeted this and was surprised at the responses, including the twitter account of @office365 itself which let me know they did support windows phone 8.
As @aharpaz suggested, my problem was that I was not saving the appointment to the correct calendar on my phone. Turns out, that when you press the “+” to add an appointment on the Windows Phone 8 Calendar app, you have to pick the correct calendar to save your appointment two. Besides Hotmail and Exchange, I have about 20 other calendars that have somehow worked there way into my life. Once I selected that calendar, WP8 seems to remember that for subsequent appointments.
Hope this helps.