You don't need the Circle Pad Pro for Resident Evil Revelations, if anything it's detrimental to the experience imo. Without the Circle Pad Pro you still have a little awkwardness to the controls that the Resident Evil franchise needs and has had since the very first game.
Download the demo, try it out and you'll see what I mean. :oD
Being able to download and play demos on the 3DS is a good sign for what we're going to see on the Nintendo Network for the U when it's released, and they certainly do their jobs too...I've decided to buy Dead or Alive Dimensions after trying out the demo. Great stuff!
And if you're anything like me then walk around with it in Sleep Mode because you'll find the StreetPass Quest and puzzle pieces that you collect very addictive.
Congrats on getting a 3DS, I honestly couldn't live without mine now!