The Onaroo Teach Me Time Clock is the simplest and most effective tool I have found for smart toddlers (and their parents) struggling with early wake times. Yes, this clock can teach your toddler time with buttons that talk, but the best feature is ability to set the hour at which it turns into a night light and the hour at which it turns green - the indication to your child that it's ok to get out of bed! Let me repeat that:
This light turns green at the hour you determine it's OK for you child to get out of bed (or their room).
At our house, every bed time cuddle and hug closes with, "See you when your light turns green". Try it!