In the latest OXM Report on Inside Xbox, Mike Webster, Director of Marketing at Capcom, confirms that you will be able to run and gun in Resident Evil 5 dispite the demo’s inability to do so.
You can use the old controls, which apply to Resident Evil 4, or for you Gears of War fans, you can use the what they call “Action Controls” which will allow you to move while you shoot so you won’t remain stationary while firing.
Listen in at the 1:30 mark for official confirmation.