Well since it seems like you already ordered, I will start out with a hearty: WELCOME!!!
And welcome to WPCentral!
I too was with the iphone for awhile all the way to the 4s and I got a bit bored. I didn't go to android though, I came right to WP. The Lumia 920 is my first windows device.
To address your concerns however (even though they already seem to have been addressed). The keyboard is actually pretty awesome on this phone. I can't say since I've never used an android personally, and only friend's, but it's better than the iphones. The guessing it does for what words I want to do was really inaccurate at first, but after a week or so (I text a lot so this time may vary) it could very easily guess what I wanted to say and I can get a few words out without even typing them. I only once was able to type out a whole sentence using the word suggestion based off the first word..
You can also voice text, similar to Siri. However, you cannot add punctuation... But it will add it for you at the end of each sentence and will even add question marks where appropriate so if you want to do sentence by sentence that works, though kind of annoying.
I don't have any music on my phone. So I cannot really help you here. However I do know that there is a windows phone sync program for Mac (which I think was linked in an above post). But also dragging-and-dropping should work for music. Worked for my pictures
(yay awesome camera!!)
IE is the default browser and is pretty well integrated in the OS. It does have some things that get a bit "annoying"... When you close the browser, it doesn't close any of your tabs so you pretty much have to do that manually which isn't bad when you realize the 2 seconds it takes to do it. Also, there is no forward button... Keep in mind there is technically no back button in the browser as the entire phone is one giant "history" log including the sites so the phone's back button is used for everything (took me a day or 2 to get the hang of that coming from the iphone where everything was segregated). IE10 does not support flash. And some sites wont "work" on mobile mode and will require the browser to be in desktop mode. A quick settings change really if you happen across a site. Most of the web is moving away from Flash and even android wants to stop supporting it so im not overly concerned here.
Camera.... oh the camera... I love this thing... great pictures and a beautiful screen. The screen is so amazing. It's bright and clear and crisp. I do not have a screen protector on it and I have 1 slight scratch (nothing major, need to kind of move the phone under the light to see it) and I think it came from my jeans having one of those little outward button clicker things on the outside.... idk... but I don't feel like I really need one much. Not much is "hidden" for the camera... except you can't zoom.. or I haven't found out how... which I find odd.. but they probably don't want you ruining the picture quality when zoomed in. Image stabilization is awesome. You can download "lenses" which do some cool things. Like smart shoot that takes 5 pictures at once and you can interchange them to make 1 great photo (STOP BLINKING PEOPLE!!
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overall for apps.. get used to being on the backburner for the "latest and greatest". A lot of iphone games use free software like unity or UDK that will just port the game for them. And these engines don't support WP8 yet, though they have said it's coming "soon". Some programs like adobe air will publish your flash games to iphone code. So a lot of devs can't really port WP8 until the tools they use support it. Unless they wrote it themselves then they just need to move some code from obj-c to C#. there are most of the big ones though. words with friends, draw something, etc... There are also "knock offs" which sometimes turn out better... No temple run yet (though as soon as unity supports it, temple run will be a click a way from being ported to WP8... more or less...) but we have ragdoll run... which is a different, though similar concept of distance and obstacles.. kind of a fun game though... plus the xbox integration.. if you have a gold live account, you can chat with your xbox friends from your phone.
overall the phone is great. It needs some things here and there but other than that, I love it. But obviously all phones need something to make them better or you wouldn't be looking to switch from iphone and android
Live tiles are actually really cool too..
Again welcome and remember, if you have any questions, feel free to ask anytime.