title: What exactly is Arel in Rails 3.0?
body: <p>I understand that it is a replacement for ActiveRecord and that it uses objects instead of queries. </p>
  
  <p>But...</p>
  
  <p>why is this better? </p>
  
  <p>will objects/queries be "easier" to create?</p>
  
  <p>will it lead to more efficient SQL queries?</p>
  
  <p>will it be compatible with all major DBs? - I assume it will.</p>
  
  <p>will it be easier/harder to use with stored procedures?</p>