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The twitter integration is probably due to Zuckerberg not being a huge iPhone/Apple fan who doesn't really hide that fact... And what else is there to sync with? Anyway - you can link your twitter with fb so you synchronize your spam if that's what you want :p
Regarding your iOS criticism, it's true that it's more evolutionary than revolutionary. Not too impressed, most of the time it was a "finally" feeling I got, except for 2 moments: 1) when I saw location based reminders, which is pretty cool, and 2) when they presented iMessage (because it seems to be a big "up yours" to the carriers) All in all - it's just a major polish of the OS, without breaking their UI. Nothing really disappointing, but nothing groundbreaking, except for the iCloud integration.
The Wifi/Bluetooth on/off switches is something you'll never see on any Apple device. It's against the "it just works" philosophy. It's technical, and 'users' don't have to know about this stuff. Not wanting these toggle switches forces Apple into looking for more power efficient technologies and better batteries and forces them to innovate. Currently I can easily get through the day with my iPhone 4, WiFi and BT on all the time, and my BT connected to my carkit for 1 to 2 hours a day, heavy phone useage, playing music in my car all the time (not charging since my iPod connector kit is too old - on the contrary, it leaves my phone's display on all the time). I usually have about 30 to 40% battery left when plugging it in at night. My colleague with his Samsung Galaxy S II can only dream of something like this. Without his toggle switches, he doesn't make it through the day. It is true that with them, and manually managing them carefully he squeezes out 2 days, but that's not worth the hassle for me.