Topic: languages, tools and jobs

I am looking for a new job.
I have experience with PHP, mySQL, postgreSQL, some Python, some little bit of Perl, moderate Apache experience, etc. All open source stuff.

First of all, every ad in my region (St. Louis, Missouri, USA) wants people with VB experience, ASP, .NET, C#, MS SQL Server, IIS. All NOT open source stuff.
Some people are looking for Java developers, but not many.

I've talked with a couple headhunters who say the same thing -- if you want a job, you better learn MS technologies.

So my questions are two:
Is it really true that the 'real world' is using only MS, when there are perfectly powerful open source packages available?
How much different is it...that is, if I decide to 'turn to the dark side' =) will I be able to pick up VB, ASP, etc relatively easily?

well... most of MS technology is fairly learnable, once you learned to deal with that documentation monster msdn (hint google.com/microsoft searchs way better than the msn search).

Thanks.
Some years ago I played with some VB. Looks like I'll be diving back in. Need to get me the C# compiler and a copy of that MS SQL Server too.
[...the though of this makes me cringe...]