And in Kanada 1.5 is king. It made a comeback actually. Everyone on Rogers was forced to upgrade to 1.5 or have their data blocked and calls routed to tech support. Many "upgraded" from (rooted)1.6 to (locked)1.5. So they must be on to something.
What's wrong with 1.6? It takes a little more time to develop a phone than to suddenly bless 2.1 that comes out in the middle of development. As long as the hardware spec can take 2.1 then the conservative manfs and providers will push 2.1 later on.
Feel sorry for folks with 2.1 capable phones that are stuck on 1.5 because the provider says it is good enough.