I can't see any security issue in syncing iPhone and your Mac via wifi:
- the phone has to be a "known" iphone to iTunes on the machine (possibly the first time via USB)
- you use a well secured WPA MAC address whitelisted wifi network
So what's to worry about security....
I can't believe I have to explain this again... -.-
4 words: WPA has been cracked.
Want more words? Ok...
I can only assume by your post that you're new to Apple's UI strategy.
Apple is all about EASE of use.
I could stop right there, but I'll explain...
The idea is that if you have quarter of a brain.... and it's damaged....and drowning in alcohol... you can still use Apple's products.
It's one of the main reasons why they are gaining success over Linux and the like. So understanding that, expecting Jane (the-quarter-brain-alcoholic-tard) Doe to know how to setup her wireless access-point with a secure WPA encryption (impossible btw since wpa being cracked it's not truly secure anymore) and with additional mac-address white listing in place is SO far from anything even remotely like Apple's definition of ease of use or simplicity that it's laughable.
Bare minimum, Apple would REQUIRE confirmation that the network is secure before allowing the connection, and with all the third-party wireless routers/APs out there, there is no way for Apple to interface their software with the competition's firmware to coordinate such security confirmation.
It's just not going to happen.
It's not even practical in any business sense.
Even implementing it and making the option available for those interested would just flood the "Genius" Bar (geniuses in quotes on purpose) with too many non-apple hardware wifi network configuration questions (as opposed to apple product related questions, which the "Geniuses" can parle into accessory sales as they often do). And paying the Genius-drones to spend hours answering those non-apple network related questions is not a good business strategy. Especially not in our ****** economy.
Additionally, to be useful the sync would have to be initiated by the iPhone, and since any wifi network can easily be configured to be identical to any other network, the iPhone would have no way to confirm that the network it is attempting to sync on is the known SAFE network before it broadcasts your authentication (not something you want to be broadcasting on just any network).
Your phone would just eat battery life checking if the network is available, then checking if it's recognizable, then secure, then checking if the expected itunes server sync software is running and ready. All being done over a wifi radio which is far less efficient than a properly implemented Bluetooth radio (Talk about killing battery life).
And then there's the problem of the lack of pairing protocol for wifi.
Bluetooth on the other hand was designed from the get go to be a replacement for wired connections. So Apple could EASILY restrict the pairing on the iPhone to a specific machine (or a set max number of machines, as is done with iTunes syncing via USB). The same can't reliably be said for wifi.
Finally, anyone on the wifi network can easily EASILY sniff packets or poison the DNS cache and redirect the traffic to a malicious server.
That task is arguably easier than setting up a secure wifi network.
AND..
(yes.. ok...I lied, there's more)
Regarding the speed issue...if Bluetooth 3.0 were to be implemented, the speed of communication would be up to 480 Mbit/s which would leave 802.11n with it's 300 Mbit/s rate in the dust (and that's N's TOP speed under absolute PERFECT conditions).
...
Now an induction charging option...why Apple hasn't implemented THAT for their products, especially with Steve's LOVE for streamlining the cases (and dislike for screws/seams/connection-ports) is BEYOND me.