GGarramuno wrote:

> Can extensions to base classes be kept within a specific namespace
> only?

This is possible in current Ruby with libraries (See 
http://uweb.superlink.net/~dblack/ruby/behaviors/ for a great library 
David A. Black wrote to do exactly this.) and will be in the next bigger 
revision of the core language. (Rite, or maybe even in Ruby 1.9)

Regards,
Florian Gross