I agree that it is way too early to move to 1200 unless you create a dynamic design that switches according to user resolution. Furthermore, with widescreen monitors becoming the norm, most people will rarely keep their browser windows maximized to the full resolution. This will create problems for 1200px fixed width designs.

I do think grids in web design are a major step forward. After using fixed 960px grid designs (via BlueTrip CSS and 960.gs) on my last two projects, the productivity benefits of fixed grids on the web is clear. Grids have really changed the way I think about web design.