There are constantly promos of one sort or another, either by MS or Nokia, to get what you're asking for. You can download all the tools you need to develop for phone, free. When you get close to having a ready to publish app, if you contact your area's Nokia Developer Ambassador, you can get a free Nokia Premium Developer Program token. That includes resources on Nokia's site, a token for Telerik's RadControls for Windows Phone ($99 value), token for Buddy (don't remember the value), and there's something else I'm not thinking of at the moment. Oh - and two Nokia Support Tickets (I don't remember how much, but not cheap). Free. Need to test it on a phone before publishing? Nokia has real phones set up somehow that you can access online. Not emulators, but real phones. Still not good enough? Make a case to your Ambassador, and he can get you a loaner. Publish your first app? He'll give you a free Lumia 800.
Join the DVLUP program, and earn points for what you develop, and get merchandise for those points. I got six RED wireless charging backs for Lumia 822. My wife has one on her 822 and I sold the rest on ebay, for more than retail (because you can't get the red backs anywhere else - at least that I know of).
Area Nokia Ambassadors run their own promos for developers that live in their assigned regions. Rich Dunbar, leader of Nokia's Ambassador program, runs promos for all developers in the Nokia PDP program (at least those who contact him to participate).
That's not to mention the Microsoft programs. I've gotten $200 in gift cards from MS just for updating a couple apps this summer. I don't remember what the promo is right now, but MS is running a promo as we speak.
There's no shortage of promos for developers on Windows Phone. And did I mention that I can write an app, get DVLUP points, use the same app to enter one of the Ambassador's drawings, and then turn around and get the MS promo, again, for the same app???
No, there's plenty of promo'ing going on for developers when it comes to Windows Phone. And you can develop for the phone with .NET... Either VB.NET or C#. There are TONS of .NET programmers in the world. So there's no shortage of developers who know the languages required. It's just a matter of convincing them that it is worth their time to 1) learn the design language, and 2) write an app. And both MS and Nokia are working on it. The word is out.