I have a typical <i>in front of the screen job</i>, just walking to and from work and from meeting to meeting. 
I found that 10000 steps were not much of a problem for a typical work day, if I consequently walked.
No elevator, no bus.<p>10000 steps should be about 4 to 5 miles or 6 to 8 km. 
I always thought this is realistic for a typical work day, but
your comment made me thinking that maybe my tracker is just off. I should compare it to a GPS log one day.