And who said 1.1 or 2.0 titles won't play in older players? I thought the only thing that won't work are the extra stuff that requires the higher specs. Everything else should still work the same. So if you buy a player knowing what it can and cannot do -- or simply don't care about the extra stuff -- then you should be fine.
Of course, it's certainly possible that there will be some unforseen glitches that need to be resolved (via firmware update or whatever) for the older players when playing 1.1/2.0 titles. But that seems to be something that comes w/ the territory no matter which format you choose -- even the old SD format had problems w/ older players handling stuff like dual layer discs during the early years.
Time will tell...
_Man_