Any new Latitude w/13" screen coming?

Improving does not mean it's the same build quality as Latitudes. New Latitudes are very well built, have a good chassis structure, and are there for business people to drop and spill coffee on the plane on.

XPS is there for the "bling" factor. That's it. It's small and pretty, but not nearly as durable.

Battery life is not even close also, you are looking over 4-5 hours on just main 9-cell alone on Latitude (with judicial power management), however, you also have a 6-cell bay battery which XPS can not have.

Weight is not "too" dissimilar, and D630 also has better included warranty, resolution, pricing as well as similar graphics (8400gs equivalent). Off the top of my head, I can't think of any reason to get 1330 over D630, unless those .4-.5 lbs are really really important, you don't care about resolution, and you must have the look.