iOS 4.3 isn’t arriving until next week on March 11th, but it appears replacement iPhone 4 units have already started to come shipped with the latest iOS.

iPhoneinCanada.ca reader Arif emailed us that his replacement iPhone 4 from Fido came with iOS 4.3 pre-installed. He also mentioned Personal Hotspot works great on Fido. Currently, the only way to get an official build of iOS 4.3 is if you have an Apple Developer account.

Having an iPhone with iOS 4.3 pre-installed means unlockers won’t have an older baseband. So if you’re looking for warranty repairs, keep in mind your replacement iPhone could have the latest firmware installed.

Have you had a replacement iPhone 4 recently? Was iOS 4.3 pre-installed?

Thanks for the email Arif!