Lots of complaints out on the t'interwebs about this.
I sort of understand what crApple are trying to do. It's so you can disconnect quickly from slow networks but still connect to your preferred ones like home without constantly having to disable and re-enable wifi when in different places.
What I've seen most complaints about is that because wifi doesn't really switch off now, that if you're out and about, that you still repeatedly get asked to join new networks as the phone detects them. Things like BT wifi etc.
There's a setting in Wifi settings where you can switch that off, and it works, now you no longer get connected to new networks automatically or asked to join them.
Of course "please don't call me Surely" mode still works and that's actually a bit better now as you can turn that on then put wifi back on so only tluebooth and your phone's mobile functions are off, still leaving you with connectivity. Maybe it's always been like that though, I don't know in honesty.
Personally, while it took me a few mins to get my head around what they had done, it doesn't really bother me that much. It's not really wifi and bluetooth that kill battery, it's the phone searching around for a mobile mast which kills it. So in that respect, this works better IMHO. You can be in that pub in the country with ten foot thick walls and no mobile reception, turn airplane mode on and still use the pubs wifi, so saving your battery from being drained by phone hunting for signal, but still be connected to the outside world.
The London Underground and wifi is probably another good example where this will save battery and be useful.
But I can understand why people don't like it. It's typical of crApple's attitude of, that's how it works now sod off.
Oh and about that pub in the country, my phone would be off, I'd much rather be drinking and enjoying my solitude than staring at the fecking screen,