I've worn a Jawbone UP for the past year and tend to average between 7,500 and 8,000 steps/day.
This is doing nothing particularly special, but I do work in a large office in an urban area, and I walk around it a lot during the day. I find myself going to the far printer or taking the long way to the restroom. I will typically leave work with between 5-6k steps, and then even if I don't do much the rest of the evening I'll still accumulate the remaining 2-3k around the house.
If I go to the gym or take my dog for a walk it's not uncommon for me to have 11-12k steps in a day.
So, yes, it's quite practical to take 10,000 steps a day, but unless you're working out daily you might have to get creative with how you accumulate them all.