Very interesting acquisition. Feel like it's too late to really hope for native sleep tracking in watchOS 4 next month, so the timing seems odd here. Otherwise I'm really excited to see Apple get into the sleep tracking game.
When iOS 8 launched with HealthKit I went on a bit of an app spree to see how much quantified self data I could get. Started using apps to track calories, got a Withings Wifi Scale, and even made Drink Keeper since I couldn't find any decent B.A.C. HealthKit apps. Sleep tracking is the one thing that I still want to record but can't find an ideal way to do it.
I've tried a bunch of options, from the 'put your phone under your pillow' apps, to watchOS apps, and even got an Eight Mattress Cover, which I love for bed warming but our cat has made sleep tracking very inaccurate. They've all been pretty good, but I still feel like I have to go out of my way a bit to get accurate data in a way I don't have to with step counting for instance. So it's interesting to see Apple jumping into this space with some hardware, but I'm curious to see what they actually do with it.