What I like about desktops is the ability to upgrade continuously (for the most part) without discarding already purchased systems, or only making back a small fraction of what was paid in the first place. In addition, if you work with desktops you will generally always be on top of the technology and it will last longer being stronger for the same money.
Not to say laptops don't hold benefits, but I think I'd rather buy a cheaper mobile laptop for my on the go tasks and then have a desktop for gaming. Not like I don't' game in the same spot every time anyway.
Also Larry, if I do go the route of the XPS, it'll definitely be the outlet, gotta love that place