After receiving several messages regarding this photo, I had to find out the truth about it. It did not look like a storm cloud associated with an approaching hurricane and the edges appeared Photoshopped. Not to mention, the water was just too calm.
Thanks to the message board at Snopes.com, one person was able to find the same photo from a Twitter post back on August 12, 2011. The photo was attributed to a storm in Pensacola Beach, FL.
Readers have also identified it as a shelf cloud.
I can't say whether it is a legit photo but I can most certainly state that the photo was not taken of Hurricane Irene.
The photo has been making the rounds on Facebook and has been attributed to Irene's landfall in both North Carolina and Virginia.
You can read the Snopes thread here and view the 8/12/11 Twicpic here.
As a follow up, I received this later today and it appears to be the from the same system in Pensacola: http://barrierislandgirl.blogspot.com/2011/08/best-storm-photo.html So based on this pic, it does appear legit...just from a different system in a different state.