On the surface this seems relatively straightforward, but I am at times a cautious person. Before I lept in with both feet I did some Google research to see if I could figure out what impact, if any, CC licensing might have upon my powers as copyright holder. I know full well that it doesn't replace copyright but it does interface with it. Unsurprisingly I am finding it difficult to wrap my head around the ramifications. In this respect I am not alone: people seem to be a bit confused about how Creative Commons licensing works, even when they're high-paid corporate lawyers or professional writers focused on the photography industry. Some folks have, as near as I can tell, entirely misunderstood how this works and have subsequently posted hysterics about the Creative Commons license as it applies to photography and the rights of the photographers. There is also plenty of evidence proving that even with Creative Commons licensing, violations can still occur -- although that's hardly unique to CC (see the above link to Chris Gregerson's story)! It's hard to separate the signal from the noise and find any truly authoritative answers to the questions that are being raised, be they legitimate or irrational.
But putting the FUD authors aside, Lucy still has some 'splaining to do. For example, one of the big problems is that Creative Commons doesn't provide a great deal of clarification about what constitutes "commercial" work. For example, if a not-for-profit wants to use one of my photographs in a flyer they're free to do so under the "non-commercial" part of the license so long as they provide the necessary attribution/URL linkage. However, this is where the grey areas start. What if a newspaper wants to use the image for an article in a story running on their site that requires a pay-subscription to access? Would that not be considered commercial use? It would seem so. Now, what if the site doesn't require a payment for access but uses advertising banners to go beyond supporting itself and into the realm of generating revenue? What then? And how about the image appearing in the article itself? The answer is readily apparent if the story revolves around the photograph, because then it is simply "fair use" and I have no claim. But if it's something they're using to illustrate the story or advert, what then? My rights as the copyright holder with this license on my image are far from having precedent in the courts. I'm also uncomfortable because CC doesn't make it terribly clear what happens, once I've licensed it as free for non-commercial use, to my ability to license this image out should an opportunity present itself for the (ill-defined) commercial usage.
If I hadn't recently had dealings with a business entity for the right to use one of my photographs I don't know that this question would ever have occurred to me or been an issue. But I have, so now it's a concern, because I want to protect myself as well as the person I was dealing with. Two weeks ago, after posting one of my photographs, I was asked if I would permit it to be used on a web page for a business. Without the kindness of the business owner the opportunity to shoot that photograph would never have existed! Because of that I was all too happy to grant usage rights, the only restriction being that I receive credit for the image. They seemed okay with that and since we both understood it was a non-exclusive right I had granted to them everything seemed okay. Now what happens if I convert that over to CC? What happens then?
Perhaps I am being as paranoid as some of the article authors I linked to above. Maybe I just need somebody to point me to the definitive guide that says "Look, dummy, here is what you can and cannot do once you've licensed your image under 'CC attribution-Noncommercial-No Derivative Works 3.0'." I have to say, though, until I have better answers or feel more comfortable with this I'm going to stick with no CC licensing and just the default copyright notice.
 I am not a copyright lawyer, nor do I play one on TV, but plenty of talented people ARE and I have a legal plan through my employer that can quickly put me in touch with a lawyer for almost any need I might have. This leads me to having a high comfort factor (known as a "warm and fuzzy feeling") about leaving a standard copyright on my photographs.