You'll have to use an AG film over the screen for matte e.g. this.
As for storage, the WWDC slides show the SSD is not physically soldered onto the logic board, but as a separate component. Most likely a proprietary connector, which rules out most third-party replacements, however I'm sure OWC will have their replacement options available soon.
I'd wait for product reviews to see, but it looks like the screens are still quite glossy, despite the 75% reduction. As for the SSD and RAM, yep... it sucks, but these are basically non-upgradable, unless you want to have Apple upgrade them at exorbitant mark-ups