The internet appears to love Windows Phone 8.1 this morning, I've seen nothing but at minimum, warm feelings for it. For example:
I think Windows Phone 8.1 delivers on all these fronts. With Cortana, it has a splashy, highly demonstrable feature—though one I hope will deliver genuine value too. With the new hardware support, we should see more phones at more price points in more markets than ever before. With Universal Apps, we have a platform that can (almost) seamlessly span the phone, the tablet, the PC, and before too long, the console/TV, too.
The result feels a whole lot more mature and a whole lot more capable than its predecessor. The 0.1 version bump, chosen to align the phone platform with its desktop sibling, belies the true nature of this upgrade. It is substantial, and makes Windows Phone tremendously better.
Consenus is that with 8.1, Microsoft has pulled even with Android and iOS, though notably not ahead. And then there's that barren app store to contend with.