"Kellex" reports to droid-life that "After receiving a tip that Verizon may be blocking Wireless Tether from the market, I decided to do a little digging on the variety of devices I own. Sure enough, from all of my phones, including the Nexus S I have running on AT&T, I was unable to find Wireless Tether in the market. So to see what was really going on, I jumped into the browser-based Android Market to see if I could find the app and definitely did. But what you are seeing [see chart], is my list of devices, all of which cannot accept this app".
See "Is Wireless Tether About to Get the Android Axe? Carriers Finally Starting to Block it?" - here.
I am following the tethering issue for sometime now, and so far saw the way AT&T handles it - by detecting "suspicious" traffic patterns, and sending customers a note (see "AT&T Detects and Enforces Tethering Policy" - here and "Sandvine on Device Awareness (Tethering Use Case)" - here).
Will Google follow Apple? Apple's iOS version 4.3 introduced the "Personal Hotspot" function which allows tethering - but it took them a while to do it, maybe in order to comply with AT&T's service policy (see "Someone doesn’t like the Ipad Tethering" - here).