The touch-enabled Eee PC model(s) could come in the form of a convertible tablet although Shen wouldn't specify -- he only promised more details in Q1, presumably at CES. Unsurprisingly, ASUS has no plans to put Vista onto Eee PCs at all.
Well, the model number is a possible clue -- ASUS' Eee Slate B121 has a 12.1-inch panel, so P1801-T may point to this device having 18 inches of screen.