There are lots of gnostic writings from around this era (2nd and 3rd century CE), and most all have some ideas in common. Such as...
- Being close to God is a matter of gaining the "right" knowledge. Very popular in Greek culture (think of all the famous philosophers), and you betcha its a big deal with New Age enthusiasts and adherents today. The fascination with knowledge being the key to salvation is attractive to many
- The idea that Jesus was a spiritual being that needed to be set free from the fleshy prison he inhabited. I haven't read the gospel of Judas yet, but I think there is some mention of this in there. Anyhow, this dichotomy is far from Jesus Jewish identity, roots, beliefs, and practices.
Basically, the gospel of Judas is something scholars have known about for a while, but there is nothing too shocking in there to many. I am sure it will get lots of play thanks to the timeliness of Dan Brown's little potboiler.