Quite the coincidence - I just started doing exactly this a few weeks ago, and am fact am reading this at 5:30am my time (when I should be coding :P). It has worked quite well for me as I work on my app.
I'm a bit more tired in the evenings and go to bed a bit earlier than I used to, but seeing as how I would just waste time in the evenings playing Jetpack Joyride, it's a very good trade to make.
I bought a coffee machine that has coffee waiting for me at 5am, and I also use the Sleep Cycle app which at the very least provides a placebo for making me wake up more alert. ;)