Do people really consider OAuth2 difficult to implement? Also, not trying to knock BrowserID or say that it'll never work, but due to browser compatibility thi

Do people really consider OAuth2 difficult to implement? Also, not trying to knock BrowserID or say that it'll never work, but due to browser compatibility this is still probably 5 years off before I'd begin using it. From what I can gather it requires postMessage which alienates IE7 users.