Is there going to be any difference in applying the CSS Media Queries for detecting the iPad 3 or the new iPad?
Also the iPad 1 and iPad 2 returned device-width as 768px in both orientations. So is that the same on iPad 3 as well ?
The Media Queries for the new iPad (or iPad 3) remains almost the same. So if you check for min-device-width as 768px, it would still work for the new iPad. However, to give a more specific query, you can check for device-width between 1536 px and 2048 px.
There is a very good tutorial on using CSS Media Queries at http://itunes.apple.com/in/app/designmobileweb/id486198804?mt=8