The Metasploit Project has just officially released version 3.0 of the framework on their website. 3.0 is a complete rewrite of the framwork and is written in Ruby. It currently contains 177 exploits, 104 payloads, 17 encoders, and 3 nop modules. It is a fantastic tool for penetration testing, and best of all -- it's completely free.
Read their blog entry on the new of the 3.0 release here
And get yourself a copy of Metasploit 3.0 over here
Enjoy!
Shawn