Can Panels provide a panels context based on the URL string or URL query?
Page Manager can take arguments from the URL and provide them as context.

For instance if you create a path in Page Manager lik foo/%bar/%baz both 'bar' and 'baz' will be automatically available as Arguments.  You just need to tell Page Manager what it is looking for (i.e. should it be a taxonomy term id? a node number? maybe just a plain string...)