In regards to updates I don't think that will be an issue with the 8X or the 822. I had the Trophy and got every update Microsoft released for WP7. I bought the 822 over the 8X, but the only Nokia app I use regularly is Nokia music. I'm sure I'll use drive when I travel, but I haven't tried it yet.
I just got the HTC 8x on t mobile the Nokia 810 was boring and low screen resolution and only $50 difference on t mobile maybe 100 dollar difference I would of considered it. If t mobile got the Nokia 910 would of got that for sure I think 4.5 is perfect screen size. The 8x is nice though