I see that all the usual suspects are there, defending what should be unacceptable, and the same arguments about the annual upgrade parade I've been making for about 6 years. The thing is I've seen and touched the '10 product a little this week. It did not crash on me (yet) however it did seem much slower at every task I asked it to perform. Good to see that all the blindly faithful autodesk salespersons, like James Wedding, and Laurie C, are right in there touting the company line.
I'd say go ahead and install it, and experiment with it, just don't migrate all of your projects, before you find out if A) your hardware is up to the task, and or B) the performance issues are not going to impact your business model (production).
Also be warned, there are a couple of interesting 'gotchas' when it comes to setting up the 'new' line coding stuff.