[gtirloni]

I will agree with Office but I've a hard time seeing AD disrupted by anything else. The alternatives aren't better and/or are a support nightmare.

And with Office, it seems the Office 365 offering with the web clients has a very good shot at technically beating Google Apps... if they can sell it efficiently is another matter.

[dredmorbius]

I'm not saying that AD is easy to disrupt (the primary challenge is that there's no one clearly superior replacement), but that if you crack it, a massive benefit / bonus of Microsoft's product line is voided.

[gtirloni]

I got it now, thanks for the clarification. And I agree.