I have had no problem with any drivers or any software running on windows 7 builds. All of the builds have been equipped with everything you find in vista, plus the additional windows 7 features -- so yes, they do all have windows firewall installed. Also, build 7048 comes with one of the largest changes for the RC -- the ability to disable certain windows features. I know disabling windows features has been available for quite some time. This takes it above and beyond so that you can tweak exactly what you would like installed in Windows. http://www.neowin.net/news/main/09/0...ures-on-or-off
In my experience, the builds have been tremendously stable. I have been using windows 7 as my main, and only OS, since build 7000. Revs, I have an ASUS P5Q-E and the SoundMax drivers have worked fine for me. As far as video card drivers for windows 7, both companies have now released preview drivers for the OS. However, I continue to use the Windows Vista x64 driver packages for the Nvidia drivers because they work just fine on Windows 7. While they may not be WDDM 1.1, I do find that performance in games is better than the WDDM 1.1 drivers currently available for Windows 7.
So far, any of the builds that have been released are set to expire August 1. However, that applies to the betas and pre-rc builds (7048). Once the RC is released next month, it will have an extended expiration date. Also, I know there has been a lot of speculation on the release date of Windows 7, but the dates I keep hearing are RTM in August, store shelves in October.