IPS 6.0(1) was originally planned for release this past summer to coincide with ASA 7.2(1) and ASDM 5.2(1).
However, there were changes in feature requirements for IPS 6.0(1), and so IPS 6.0(1) release has been delayed.
No specific date has been publicized for the IPS 6.0 release, so further discussion is limited on this Public Forum.
For more information on the release date, and new features being added into 6.0, you would need to contact your Cisco Sales Representative.