Not less than a week, SE officially launched W700i. Now the rumors are up again about another Walkman phone, W830i. I think picture speak more than words, so take a look at the phones. Seems a mixture of the preliminary shot of SE K800i and the officially launched one.
However, this site have already posted specs of W830i. According to them, it is a quad-band phone, weighs 108 grams and has a 2MP cam. In my opinion it seems to be fake and will be a rumor until anything comes out of those SE guys.
UPDATE: SE has launched three new phones along with W830. Press Release.