Alternative proposal ... not backwards compatible

paramify.js

var http = require('http')
var paramify = require('paramify')

var router = paramify()
router.get('intro/:greeting', intro)
router.get('showtimes/:start/:end', showtimes)
router.default(notFound);

http.createServer(router).listen(1337, '127.0.0.1')

function intro(params, req, res) {

  res.writeHead(200, {'Content-Type': 'text/plain'})
  res.end('Greeting was "' + params.greeting + '"\n')
}

function showtimes(params, req, res) {

  res.writeHead(200, {'Content-Type': 'text/plain'})

  var message = [
    'Show starts at', params.start, 
    'and ends at', params.end
  ].join(' ') + '\n'

  res.end(message)
}

function notFound(params, req, res) {
    // ...etc...
}

console.log('Server running at http://127.0.0.1:1337/')

I guess change .get() to .match() too.