For months there has been speculation about Apple announcing an ultra thin tablet computer which has been dubbed the iSlate. Now Microsoft has trumped the announcement (in terms of the timing at least) by presenting 3 slate PCs running Windows 7 from HP, Archos and Pegatron.
It doesn't look like technically the slate PC is anything but an incremental improvement on the tablet PC concept, but the point is that in terms of desirability and utility to the user, slates may be the breed of products which finally establish the tablet as "mass market".
For now, analysts are expecting the slate to stimulate growth of the $950m (£597m) US market for tablets, but I think the impact of the slate will either see it become considered a whole new format distinct from tablets (tablets often still have keyboards), or a redefinition of the tablet. It will also be interesting to see, as the price reduces over the next 5 years, what this does for eReaders such as the Kindle or the Sony. These devices can still boast the strengths of e-ink readability and long battery life, but the gap is closing.