Should BDD scenarios include actual test data, or just describe it?

I prefer option 2.

To the business user it is immediately clear what the inputs are and the outputs. With option 1 we don't know what valid data is, so your implementation may be wrong.

You can be even more expressive by adding invalid data too, when appropriate

Scenario: Filter for Awesome
    Given I have navigated to the "Show People" page
    And I have the following data
    | Name  | Value  |
    |  John | Awesome|
    |  Bob  | OK     |
    |  Jane | Fail   |
When I click the "Filter" button
Then the list should display    
    | Name   | Value   |
    |  John  | Awesome |

You should however keep the data so its described in terms of the domain, rather that the specific implementation. This will allow you to test at different layers in your application. e.g. UI Service etc..

I would say it depends. There are times when a Scenario might require a large amount of data to complete a successful run. Often the majority of that data is not important to the thing we are actually testing and therefore becomes noise distracting from the understanding we are trying to achieve with the Scenario. I started using something I call a Default Data pattern to provide default data that can be merged with data specific to the Scenario. I have written about it here:

http://www.cheezyworld.com/2010/11/21/ui-tests-default-dat/

I hope this helps.

Every time I think about this I change my mind. But if you think about it - the test is to prove that you can create a region. A Criteria met by both options. But I agree that the visual cues with option 2 and developer friendliness are probably too good to turn down. In examples like this, at least.