Not really, but Cult of Mac have found this cool concept video by Oliver Terisse showing how a Macbook Air could turn into a tablet.
There are too many problems with this concept though, like what kind of hinge would exaclty support this functionality, who wants their beautiful Macbook Air keyboard getting scratched and perhaps the biggest - we have the iPad, which is just so much more convienient.
http://youtu.be/R92jQtQuhuA
