This is just wild optimism, but a colleague of mine (a Blackberry user) said that Microsoft might be hard at work to push this phone to business/enterprise users. Yes there are obvious security issues and what not, but the way he explained it was that there are a lot of Microsoft services - e.g. Office 365, Exchange, Windows 8, etc - that businesses may continue to acquire in the future.
What Microsoft could do is - while securing contracts for these services - to simply offer Windows Phone 7.5 (or 8) "enterprise edition" phones built to work with their systems from the get-go for free. So they can offer free limited pilot programs for larger businesses, and complete handset solutions to smaller ones. They will take a loss, but they'd have multiple businesses experience the full Microsoft set-up first hand, and from there (as well as profits gained from providing services/software) make up for that loss over time.
We know they can sustain losses, but when you have a company like Nokia also supporting it, jointly subsidizing handsets may not be as big a deal. In the end, if a WP7.5/8 Nokia enterprise phone works with the MS eco-system well and users like it, then those very same businesses will probably continue buying and others will join.
Again this is just wild optimism and an outsider's guess as to how Microsoft might be thinking. In the end though, we should remember that Microsoft has a habit of coming into the game a little late, but if they persist and do it well enough, they can come out as a key player in an area. They're the type of company that is willing to take some hits and throw money at something, even for a couple of years.