I have been using CatapultC for more than 3 years. There are unlimited number of questions about it. You can read some of them below (just simply register):
http://communities.mentor.com/mgcx/community/asic_fpga/esl
It supports most of verification and implementation flows that other tools do not. I think no body in the world could have any allegation that he or she knows it completely because of its unbelievable complexity.
If you are a person who wants to show himself an active member in IEEE (1 paper in a month related to the IP developing ) you have chosen the appropriate tool.
The Catapult C version 2011a.183 (update 7) has been released in summer of 2013. In the installed program you'll see in the "About" Windows that the 2011a.183 (update 7) was released in 2013. It is possible, that this version is the latest released version.