My disappointments include:
-Same back camera as the S7. Samsung claims the software has improved though, and the Verge impression says it's noticeably faster, so those are pluses, but it's a shame it's the same shooter hardware-wise.
-Small-ish batteries. Though coming off the Note 7, that's fine. And Samsung claims the battery will degrade less overtime.
-Price. And no unlocked model yet. I'm thankful it's not more, though. I believe the S7E started at $730 (?), so $750 for the S8 isn't terribly far off, but it's still a pretty penny. At least you're getting a ton of modern technology (cough, Apple)
-No stereo speakers. Not even the Apple/HTC 10 version.
-The one odd design choice in an otherwise gorgeous phone is the fingerprint scanner placement. It's awkward and was possibly moved there at the last minute when they couldn't get the fingerprint scanner to work with the home button, but early impressions of facial unlock are, at least, positive (the Verge said it was so reliable and fast that they had a hard time filming it).
Overall, we got exactly what we were expecting. Everything else looks and sounds terrific. Admittedly, I'm not as gung-ho on pre-ordering as I thought I would be. I'll have to mull it over a bit more. The value for the S7 cannot be ignored here.