WP 8 roadmap

It's no secret that Microsoft wants to achieve a single OS good for desktops, tablets, and phones. Or at least one that shares all the APIs so developers only have to create one version of the App which will work on all. Besides being old, my HTC HD7 became obsolete the day Microsoft released Windows Phone 8, and stated that WP 7.x devices could not upgrade because there was a kernel change. I've read news all over that Windows Blue will update the Windows kernel from 8.0 to 8.1 Now I'm afraid that the same will happen to Windows Phone, and as Microsoft gets closer to tying the two systems together, they'll go through a couple different kernels for the Windows Phone, fragmenting the ecosystem even further. Do you guys see Windows Phone 8, as a safe OS with a future of upgrades, or should I take it for what it is, and not expect any new features from what I get in the box.