I just read through Volker's post on Navis 2010 and found it very informative, but of course, I have comments of my own! I enjoyed particpiating in the 2010 beta, and was thrilled to see some of my requests come to fruition (probably because everyone else was requesting them too!).
The updates to the interface (ViewCube & Steering Wheel) are helpful. Although I initially hated ViewCube, I really like it now and am happy to see it in Navisworks (and I love that we can actually turn it off, too!).
And yes, as Volker mentioned, there are improvements to the measure tool, sectioning and visualization (finally - a horizon in Navisworks).
But I think that the most important improvements weren't included (or weren't covered in great enough detail) there.
First and foremost, shared coordinates are finally recognized from Revit. So now, we don't have to worry about 'Override Transform' just because someone set up the various models out of allignment. I see this fix as a huge benefit to collaboration. Often times, we have no control over where other parties place their model (in reference to 0,0,0). (The next step will be to recognize 'New UCS' in the AutoCAD export, right Richard?)
Yes, viewpoints are exported from Revit, but graphic overrides aren't maintained. We're a little frustrated with that.
The improvements to clash detection are really exciting. Clash reports are normally so cumbersome, with hundreds or thousands of clashes in a list. The ability to organize things by folders is helpful; the automated "group clases involving item" is even better. New graphic abilities in clash detection are really helpful: the animated transition from clash to clash, the ability to view a clash in context and the transparent dimming will be really helpful during coordination meetings. Oh, and we appreciate the additional clash status of "reviewed", but why can't we make custom statuses?
We love this release - in fact, we've already upgraded to it (still using beta of course) for current projects because the new features are worth it.