I think that you will definitely be glad that you pulled the trigger on the Icon. I had been keeping an upgrade available for quite some time waiting on a device I actually wanted, the 928 just didn't quite do it for me. While there are a couple things I wish the Icon had, waiting for that one perfect phone means you'll be waiting for a LONG time! I've been around Windows Phone and Verizon long enough to know now was likely the best time to get a device that was at least close to my ideal. And I haven't looked back since!
The specs on the Icon are great and I'm definitely loving it. Just like others have said, we're not likely going to see another high end Nokia on Verizon for some time. It took them ages to finally release the Icon. Everyone new about it for months yet for whatever reason, be it testing or bugs or whatever, it took them quite a while to actually release it. So based on that and their past release history it's not likely that we will see another high end Nokia anytime soon. If ever... who knows the next "Lumia" we see on Verizon might be from Microsoft if it's more than a year away.
As you're new to the WP ecosystem, just go into it with an open mind. There will be some adjustments to be made and you may find some apps or features missing. Ask around on the forums if you need because often times there are fantastic 3rd party apps to fill many of those remaining gaps (some of which are better than official apps) but they aren't always apparent.
In any case, I hope you enjoy the Icon and welcome to Windows Phone!