Windows Mobile users are being notified by Microsoft's Total Access about Fusion 2.0 the latest offering from PhoneFusion, which provides a unified inbox for voice mail ala visual voice mail, faxes and text, all in one.
I take a slight exception to the claim of "A new feature—exclusive to Windows Mobile users—is that for the first time mobile consumers can receive faxes right on their smartphone" as I've been doing that for years with Webley/Communikate on my Blackberry and used to do that on earlier generations of Smartphones with an Adobe PDF capable client. I also read faxes on my Nokia E71 with an Adobe client, however, may Microsoft customers are not cutting edge these days :-)
Regardless this is really a very good, and useful service as it consolidates a lot of what the business user needs and is a far cry better than anything currently being supplied natively by Microsoft and easier to use than other services out there making similar claims. To be blunt, if I was on a Windows Mobile device, it would be on my list of must have applications.