title: Reactive extension - Return same observable or create new?
body: <p>I am trying to design a service layer abstraction with Rx. I have wrapped up all webservice calls using <code>FromAsyncPattern</code>. I will have multiple <code>ViewModels</code> subscribing to these observables, some can have multiple subscriptions. </p>
  
  <ul>
  <li><p>Shoud I create <code>readonly</code> <code>IObservable&lt;T&gt;</code> properties in my <code>ServiceProxy</code> class (singleton) and construct once in the constructor or should I create new observables every time in service methods and return them ?</p></li>
  <li><p>Does it matter ?  </p></li>
  </ul>