And won't be an option for much longer for new devices, Google are turning of Exchange sync for new devices soon except for paid accounts.
I heard about that. Would this also be the case for Google Apps? I'm using that as my main email address, but it's also a free version. Now you have to pay for it as well, but existing users could continue to use it for free.
And even if/when they disable it, I'm sure there'll be another way to use it with the iPhone. I doubt Google would want to kill that entire market.