I have been using Office 2010 for about 6 months now. It was a bit rough the last 4 months or so. I was also very sad that I didn't have my favorite addins such as plaxo, xobni, and others. I have been running them on a desktop I can remote into if I need them or need to sync my outlook data via these extensions. I got the new build installed after having to mess with the uninstall process. It was really annoying but it worked out. The new beta build is very nice. It's more stable, and there are several items added which didn't exist previously. You can also see in outlook how they are starting to integrate social media into email, something xobni has been doing very well for quite a while. The Microsoft social media integration isn't complete or even really working, while the xobni version is very advanced and works great.
I wish that Microsoft built some kind of wrapper to allow the previous addins to work with outlook, but I guess that's not going to happen.
Xobni - www.xobni.com
Plaxo - www.plaxo.com