If we're talking about Asus' potential PR stunts then I'd point at the PadFone over this one. It's already been reported elsewhere that NVidia wants "aggressive penetration" (oo er missus!) of the tablet/smartphone market by Tegra3, so there's the obvious theory that this new Asus device is more or less being done "at cost" to get market share.
No, I don't doubt that it'll arrive on the market, what I do doubt is that we'll see it at the £160-170 mark that the quoted "US$249" equates to. Being deeply cynical I suspect that we'll get it priced at £200-250. Personally I think they'll do okay at £200, although at £170 I suspect that they'd be VERY popular if they were available for next Christmas.
Bad news for the folks like Disgo, Archos, etc who've been content to ship low-powered, nasty kit running restricted and/or old-OS versions up until this point.