I have been using Navisworks quite a bit lately, and something that has really annoyed me is the clumsiness of setting up timeliner animations. Particularly for preliminary presentations, setting and altering the dates can be time consuming. But all along there is a Gaant chart sitting there on one of the panels which is read only and cant be edited...
|Inage from Autodesk (Gaant chart on the right)|
The other item that sparked my interest was the introduction of Navisworks being compatible with multi-sheet DWFx files. Currently you need to switch back to Design Review if you want to review a multi sheet set of documents, well now everything can be done straight in Navisworks. I am yet to test the functionality, but it looks like Navisworks will have the full review capabilities to markup drawings as well, which should be great to keep all in piece of software
There are quite a few other new features as well, check out more info here http://usa.autodesk.com/navisworks/features/