For the most part:
- One of the best displays available "close to textbook perfect calibration and performance":
http://www.displaymate.com/Pixel_4XL...t_1P.htm#Table
- 90Hz display
- Dual rear cameras (~28mm, and ~48mm with optical hybrid zoom)
- Live HDR previews and live shadow/highlight HDR adjustments
- Single front camera (90 degree FOV now though, about the same as last year's wide front camera)
- Project Soli (radar control)
- Face unlock (no more fingerprint sensor). It is apparently so ridiculously fast that there are menu options to slow it down for those that want to.
- 6GB RAM (50% increase)
- SD 855
- New neural core
- New voice recording app with live voice-to-text
- Assistant 2.0 has the entire English component stored on-phone so it doesn't need to access the internet and is therefore much faster
Rest is pretty well the same - battery is slightly bigger in the XL, slightly smaller in the non-XL. Same screen sizes as before.
Every single detail leaked months ago so there really aren't any surprises at all.
- - - Updated - - -
Hard to say. I've always got mine early and last year was the first time I paid for faster shipping. I did this year too as it was only $12. We'll see if I get it before or after the 23rd I guess.
Given how many times production-looking models leaked, it's hard to believe Google doesn't have a bunch of them ready to go haha.