I think the reason Apple didn't market this to us is iWatch and the lack of third party integration as of now. They might be wanting to show this off as part of iWatch integration or let the third party apps do the marketing.
They were supposed to have tons of 3rd party apps at launch, but they found some sort of (presumedly security) bug in the release build and had to pull/prevent apps from integrating when iOS 8 launched. There was even a feature area on the iOS App Store but it was quickly removed.
This was fixed in iOS 8.0.1, but that caused connectivity problems on the 6 and 6+.
Now with 8.0.2 things are finally ready, but now the apps aren't out or approved, so things aren't ready yet. Sadly this whole thing has been kind of a mess. I remember reading some 3rd parties scrambled to get an update out for the iPhone 6 and 6+ that disabled the Health functionality since Apple was temporarily rejecting apps due to the bug. I've seen a handful of commercials on TV already.
Sadly none of this has gone smoothly. I imagine in the next week or two we'll see the 'real' roll out. Maybe they'll make a big push again when they turn on Apple Pay.
