I like the style of photo that you might find in an Anthropologie catalog or the type that’s been coming back recently – the faded, very bright, outdoorsy portraits of people. Is this a simple desaturation? An example photo: http://www.flickr.com/photos/65149478@N06/6078090902/
First off, they’re high key exposures, the overexposure tends to wash out the contrast- it works better with a limited palette of subject colors, imo. There might be a touch of desaturation in Photoshop, but I’m not too sure about that, having seen this done many times with film.
over exposing by 1/2 stop and cross-processing slide film in c-41 chemistry will get you there.
Otherwise, doing it “properly” through pure digital means takes several steps (of which there are infinite possible combinations each with its own quirks and charms). If you google for “cross-processed effect in [insert your editor here]” or “expired film effect…..” You’ll find dozens of tutorials.