depends on the type of workout:
if it is cardio. workout first thing in the morning and then immediately after (within 20 minutes) get some healthy protein and carbs in your system. It will keep your metabolism revved up all day and you will feel great!! Dont forget to eat plenty that day and dont forget to drink your water!! Water!!
If you are weight training, the meal BEFORE you went to bed will fuel your workout. A good supper will help you have sufficient glycogen for your training. If you ate a crappy supper, then you won't make it.
I dont mind weight training in the morning, but only if I had some nice healthy complex carbs before bedtime so that I can fuel an intense workout... be warned tho!! If you want to be super lean, carbs before bed is NOT a good idea.
I am the guy on Realjock who says this: experiment! through trial and error see what your body likes to do! Everyone is different, so approach it like an adventure and lets discover what is best for YOU.