I just wanted to chime in with my agreement that the new 200m height is pretty horrible as currently implemented, since it is such an obstruction to cross-country height. However, I'm all for deterring griefers, and the planned change to make is only for specifically banned people is great.
I was going to suggest addition of LSL script calls to add/remove people from the parcel ban list, but I see that was added in 1.8 (I pretty much stopped scripting post 1.6 as SL became increasingly unusable, so missed this addition). However, is there a way to query whether a person is on the ban list?
I still don't understand why, after all this time and so many repeated requests from users, the gray squares are still there and no apparent way to change them client-side. Through all the upgrades, this continues to be a huge detriment to my experience, a major unresolved problem which would be SO easy to fix. I know how you have to plan your resources to work on the bigger problems, but as someone who works in customer service myself, I know how much it can help to solve a little problem like this with a quick/easy solution to keep people happy so you can then get on to the big stuff.
Between the performance hit post 1.6 and continued 2nd-reality-altering changes of this sort, my online habits have changed from hours each day to a brief login every 3 or 4 weeks to see how things are going. I know the world and userbase continues to grow at a rapid pace, but I can't see how growth just for the sake of growth is a good thing. Hence, problems like increased griefing.