title: Creating a multiindexed `Series` with a nested dictionary
body: <p>In my mind, what I'm trying to do ought to be straightforward, as straightforward as passing it into the constructor, but in reality it's not. I have a dictionary like below.</p>
  
  <pre><code>d = {"russell": {"score": numpy.random.rand(), "ping": numpy.random.randint(10, 100)},
      "cantor": {"score": numpy.random.rand(), "ping": numpy.random.randint(10, 100)},
      "godel": {"score": numpy.random.rand(), "ping": numpy.random.randint(10, 100)}}
  </code></pre>
  
  <p>I would like to do something like <code>pandas.Series(d)</code> and get a <code>Series</code> instance like below.</p>
  
  <pre><code>russell  score  0.87391482
           ping   23
  cantor   score  0.77821932
           ping   16
  godel    score  0.53372128
           ping   35
  </code></pre>
  
  <p>But what I actually get is below.</p>
  
  <pre><code>cantor     {'ping': 44, 'score': 0.007408727109865398}
  godel        {'ping': 41, 'score': 0.9338940910283948}
  russell       {'ping': 74, 'score': 0.733817307366666}
  </code></pre>
  
  <p>Is there a way to achieve something like what I'm trying to achieve?</p>