I still go for a dekstop for the office and netbooks for mobility.
You still get better spec/£ in a desktop than a laptop.
A desktop you can keep on slinging HDDs into.
I use my desktop as a TV/PVR and watch on a 22″ wide screen
My desktop serves as a NAS for the other computers in the house
My desktop serves as a printer server for other copmuters in the house (over wifi)
All but the first of those is doable with a laptop, but with a desktop its just easier day-to-day.
Mrs S has a massive Dell laptop, which is great but hardly “portable” and battery life isnt amazing.
I have a couple of netbooks (cost about £120 each) which I use for work with just Chrome and Excel on them and 1 or 1.5Gb of RAM. Muchos portable, and with the battery extender I can get 9hrs out of one a charge.