This does not look that appealing to me.
The screen is only has a 720p. Given the low power specs, this makes sense.
It's really big, to the point that I even wonder if it's worth it compared to just carrying a laptop.
It has no AV output other than Displayport Alt-Mode through the single USB-C port. I would have much rather seen at least a dedicated mini HDMI port on the unit itself.
Only one USB-C port, which appears to be for charging. So you can't easily hooked up a keyboard and mouse to it if you wanted.
For some reason you have to buy the $650 version to get an anti-glare screen, so the cheaper models are useless.
Yes, some of these issues are addressed by the dock, but that's an unknown extra cost at this point(I'd guess its going to be in the $100+ range.)
At $650 you are approaching low end gaming laptop territory. And you can say "just buy one of the cheaper models" but the storage is so small on those, that you are going to end up using Steam Remote Play almost constantly, and at that point, a cheap laptop would probably be a better purchase(not to mention the lower quality screen on the cheaper models).
Hell, for
$630 you can go get a laptop off Newegg right now with 16GB of RAM, a 512GB NVMe SSD, and a 5500u. You'll have a lot more power, it's arguably just as portable, there is no need for an extra dock, it has a 1090p screen, and it is a full blown freakin' computer not a single purpose gaming system. I guess I just don't see the appeal of the Steam Deck compared to something like that laptop.