A few different options here
First, as someone whose MCSE number is in the low 1,000's I've been through a lot of MS betas over the past 19 years. Like a lot of other people I downloaded the Win 10 beta out of curiousity, even though I'm mostly immersed in Linux and other open source nowadays (all the servers I work with are RHEL, and my admin workstation at work is Fedora 20). I did read the EULA and (separately linked) related policy documents. The software got installed into a KVM image that's isolated from the rest of my network (I opened thing up to register but then closed in off again).
If I were really interested in continuing to beta test this I'd leave the pipe open and let MS monitor things however they'd like. After all, that's the whole point of beta testing -- gathering data on what happens when people actually use the software. But it's unlikely that I'll be making the effort, so I'll probably just play with it a little longer and then let it expire at the end of the beta period.
Going forward people should probably keep a close eye out to see if that kind of monitoring (especially the keylogging) continue. If it does, of course that would be an unacceptable invasion of privacy and a serious attack vector that no one could afford to allow on their network. If it doesn't, then maybe those who still need to run Windows will be OK (although, being closed source, there'll be no way to know in advance if it were ever turned on again).
Here's the thing. Unlike back in 1995 when I started out, there are many acceptable alternatives to Windows in the data center, and for some of us at least, on the desktop. The enterprise class Linux distributions and the BSDs have a proven track record over the last decade. They're all high quality, fully tested and have significant support resources behind them. For the desktop Apple is an obvious choice, but despite some extremely annoying shortcomings, the major Linux distros can also work well as admin and developer workstations. When SteamOS ships next year we may even see things improve for general purpose consumer desktop applications.
I'm sure Microsoft knows all this, or at least someone over there in Redmond does. At some point that knowledge is going to percolate up to the top levels of the company and then they'll have some choices to make. The important thing for the rest of us is that even if they make the wrong choices it won't mean the end of life as we know it -- only as they (Microsoft's execs) do.