Google today announced the shift, which you should note doesn't appear to apply to older Wear watches. Starting today, the LG Watch Urbane will pair with iPhones, and all Wear watches moving forward – including the upcoming Huawei Watch, Asus ZenWatch 2 and (rumored, but highly expected) 2nd-gen Moto 360 – will as well.
Google made no mention of older watches, like the original Moto 360, LG G Watch R, Samsung Gear Live or original Asus ZenWatch, so we think it may be safe to assume those first-wave watches will remain Android only.
Google describes Wear on iOS' features as receiving notifications for messages, calls and other app notifications, as well as fitness tracking and contextual reminders, so it sounds like most (perhaps all) of Wear's functionality on Android will be available on iOS.
Though we picked the Apple Watch as the best smartwatch to date, we found its lead over Wear watches to be minimal – and we also found Android Wear gear to generally offer better value than Apple's expensive wearable. This could be Android Wear's biggest boost yet.