The options for desktop use are nice. You can attach an external monitor, and also a keyboard and mouse if you like. The mac supports "lid closed operation", so when you get to the office you can pull your mbp out, slide it under the foot of your nice 27", and plug in the displayport to the display. Plug in mouse and keyboard, hit a key and it should wake up, with lid closed, and you can use it just like that.
Or you can have the monitor next to the computer and use it as an extended desktop space. A lot of people doing page layout, graphics editing, or video/audio track editing use dual displays, placing their work on one and the pallates/clips/etc on the other. The two displays act like adjacent space and you can drag things left and right, and even have windows that are split partly between displays. It's all very transparent.
