are there a lot of opportunities in the node.js market as compared to say asp.net or php?
One can never be too sure about tech, but if something like Node was to become even more popular in the next five years or so, I would prefer to have been working away at mastering it over those five years. This is just my two cents, and not having a lot of experience I could be wrong :)
In my experience and research, there are Python (Django) and Ruby (mostly Rails) jobs out there. The corporate world tends to favor PHP, .NET, and Java. While startups and freelance gigs will either let you choose the tech, or specify one of the popular scripting languages.
In the PHP ecosystem, there are Model View Controller (MVC) frameworks such as Laravel that have features that are on par with Rails and Django. Content management systems such as Drupal, Wordpress, and Joomla are also very popular. Generally, not many developers are still writing code in plain old PHP, they are using frameworks and CMS's to buld their solutions. So I'd advise you to look into one of those if PHP is what you want.