Also: if you're already comfortable with Cake, the jump to Rails is probably quite short. I'll bet you become very productive on it very quickly.
The Python job market in New York is hot, and Django is very popular. I don't see too much other than Rails opportunities for those that bring Ruby knowledge, but there is certainly enough Rails work to keep you busy. The upside is that there are lots of CMS and infrastructure stuff that is Ruby based, but they tend to be products in their own right rather than tools to hack on. In my opinion, Rails carries Ruby in the market. Without Rails, Ruby would probably fade back into relative obscurity.