As I was driving home today, I couldn't help notice something. Microsoft's ASP.NET MVC framework is still in beta, and was only announced last October. To my knowledge, there are currently three projects in the Edmonton area based off this framework.
Castle Monorail has been around for much longer, three years or so? It's still listed as a release candidate on it's website, but I'd say Monorail is suitable for production. Currently, I am not aware of any projects in the Edmonton that are based off this framework.
I guess this is anecdotal evidence that you won't get fired for sticking with Microsoft. :)
The two frameworks have quite a few similarities. IIRC, in Austin last fall Scott Guthrie did mention that the ASP.NET MVC framework was influenced to some degree by Monorail.
Regardless, it's good news. Personally, I like both frameworks, and would prefer either of them to Web Forms. YMMV.