According to This is my next, rumor has it that one of Sony's upcoming tablets - the S1 - will available for preorder in the UK beginning on September 1st. That's still a couple of months down the road, so pricing, availability, final release date, and other details (including possible US release date) are lacking at the moment.
The S1 is one of a pair of tablets that Sony announced back in April, alongside the clamshell style S2. It houses modest specs, along with an unusual design:
Right: Promo shot; Left: Mockup of the "off-center gravity design"
9.4 inch display
1Ghz dual-core Tegra 2 processor
Front and rear cameras
It also sports a custom overlay on top of Honeycomb, but Sony has yet to let us catch a glimpse of what that is expected to look like.