You are correct in Apple copying Google on a few features and vice versa. I'm not sure about WP reaching feature parity though. I'm quite sure Google and Microsoft like Samsung will now start targeting Health on their devices. iOS 8 features pushes Apple ahead again which means Microsoft will mostly be behind the curve.
Except Microsoft is already developing features like that as well (Bing Health and wearables have already been mentioned and/or announced)....8.1 outshines iOS in many ways even if you consider it "copying."
I was on iOS since it came up and switched to Windows Phone 6 months ago just for the heck of it...and I fell in love with the larger phone choices. I've had WP 8.1 since the developer preview was released a couple of months ago and it has filled all of the gaps I gave up with iOS including a better notification center. Live tiles are huge for me. Cortana is truely the best of Siri and Google Now and is improving dramatically every week...and it hasn't even been officially released yet.
HD phone screens and features like Glance with Nokia as well as incredibly accurate map apps, Bing data for Cortana and MS apps...
Yes...apps are behind iOS and Android, but catching up every day. Honestly, there are none that I miss outside of my local bank app...and the web version works fine for me. Others that I may have used were used sparingly and most likely have a WP counterpart that would suffice.
I have to laugh at the slide they show where PC sales are only growing 4% and Apple Mac growth is over 20%. If I decided to build my own cars and sold 50 this year and 100 next year, that would be 100% growth....do you think Ford would be concerned that their growth was only 4 percent? Windows is EVERYWHERE, particularly in the corporate world. MS has made a bunch of missteps and questionable marketing compared to Apple, but by providing a phone OS that now seriously rivals the best while coming out with the Surface Pro 3 which allows corporate to provide their workers with a functioning laptop that they can also use as a tablet when needed is great.....and I think it may push Apple in a similar direction (remember talks about the 12" iPad Pro??).
I miss Apple less and less every day...