dirty little secret

smart phone，tablet端末に続き，次世代ハードウェアを担うと予想されているwearable端末。その中核となるであろうApple社の高機能腕時計（iWatch？）の発表までカウントダウンが始まりました。
little secretはa secret that is not very important（LDOCE）という意味ですが，これがdirtyを伴ってdirty little secretとなると「〔隠しておくべき〕決まりの悪い事実、外聞の悪い事柄」（英辞郎 on the WEB）という意味の表現になります。
iWatchは時代の流れを作ることができるのでしょうか。（Koyamamoto）

5 things we'd like to see from the Apple smartwatch
(CNN) -- Rumored for years, the long-awaited smartwatch from Apple may finally become reality in a few months.
The Wall Street Journal and Reuters are both reporting that the iWatch, if that is in fact it's name, will be released this fall, likely in October.

Really be 'smart'
The dirty little secret of smartwatches, at least so far? They aren't really smart in the same way that a smartphone is.
So far, the offerings from Samsung, Sony, LG and the like have operated as extensions of a smartphone, linking up via Bluetooth or wireless to, for the most part, serve you notifications that you could have seen by pulling your phone out of your pocket.
http://edition.cnn.com/2014/06/20/tech/mobile/apple-smartwatch-features/index.html