I'd say it's a realistic goal, That's what I've set too. It gives you 1 kg per week to lose which is a healthy rate plus a couple of weeks allowance for 'pauses'.
35kg lost. (November 2005 - October 2006)
15kg gained again (as at October 2010).
Back to the drawing board - Let's do this thing!
"You can't change the winds, but you can change the sails"
"Reach out and take control of what lands in your lap"