Have been reading about VS2010 and C#4.0 for a while now. Finally installed Visual Studio team system 2010 Beta1. We have been using .NET 3.5 and VS2008 for over 1 year now on all our .NET production projects, so the next version is the natural progression. Time permitting, I would share my findings as I go.
You can install visual studio side by side with your earlier versions of Visual studio. But you have to uninstall and install the release version later anyway. So I tried to install on a virtual machine. I first tried to install on a vm (vmware desktop) on my laptop but it sucked up so much memory, I couldn't even open vs 2010 and the IDE rendering was horrible (because of all the WPF stuff I guess). So I installed on a remote windows server 2008 vm server. The first thing you notice is the minimalistic features (by default). The asp.net news RSS feed is now just one scrolling line instead of taking up the whole page. The toolbox explorer etc are all auto hidden. It's a pretty clean start page with 3 menu texts. You can customize your start page (you will see that it's XAML code)
Here are some articles you may want to take a look: