By the time my upgrade rolls around (March), I'm assuming there will be better phones than the 920 out. As for WP8, I'm not sure yet. The hardware looks fantastic, and the internals are, like you said, far better than any other phone on the market at the moment, but the WP8 ecosystem is just so far behind iOS and Android right now that I'm not 100% sure. I don't care about phone gaming, but there's a few notable apps that aren't on W8 that I'd still like to use.
As for Swiftkey, yeah, you're right on that one. I was just going down the list of Android apps that I've bought. Honestly, it's a short list.