Not much more space and power. The power difference wouldn't be much over a year...we aren't talking about the difference between using a huge crt and lcd.
How much is electricity there anyway? A desktop running 24/7 uses a substantial amount of power but it's not like running a reverse cycle airconditioner.
Laptops don't use much power at all...I've had one running 24/7 for the last year and the cost is nothing compared to back when I was running a desktop 24/7 (that only had a psu around 400 watts).
A laptop would be able to run more ram.
I have an ultra here (not a netbook) that's only 11.6", dual core but has 8GB ram. Has hdmi and vga. Just missing an optical drive.