Ruby on Rails 3.0 has finally been released, after two years of development:
[UPDATED September 4th]
In addition, a Rails 2.3.9 maintenance release is out as of Sep 4th 2010:
Just select from the dropdowns when you place your order –
Rails will be installed with Passenger, and whatever other config you desire, just put it in the “Notes” field when you place your order.