@OP it sounds to me as though you heard the hype, too the marketing as gospel and then were disappointed when the additional assumptions that you made didn't happen.

Not quite sure what the WiFi bug is that you are talking about but mine is generally fine. Video calling has been available for ages and I have used it a few times - GTalk video call works fine. If you are talking about 3G Cellular video calling then I don't remember that ever being on the specifications and all the operators are *****ing about the fact that virtually no one uses it in Europe at least.
As for more than basic call support - this is a tablet that can make calls, not a super smart phone. I don't know anyone that was under the impression that this would be anything other than this.
Just becuase you can't sync your calendars doesn't make them unusable. I agree that not being able to use their own tech for syn is daft but this is a seperate issue again.
Portrait mode was, as far as I recollect, only promised for the browser (it's there) and applciations decide if they want to support portait or not.
Email apps on the tablet series have never been brilliant and agree they should be better but you are asking for corporate style features, this is an N series device, not an E Series.
Map app has basic features missing? Such as? It shows a map, it shows you where you are and where other things are. That sounds like a set of basic features to me. It is missing a few things if you were expecting a full blown sta-nav application but I don't believe it was touted as such and it is still under development.

Basically the N900 was always billed as a device for early adopters and technical users, not a mass user product so sounds as though you missed the point before buying. Glad you are enjoying the product though despite the frustrations!