pdr's comments are valid, and I agree with them. But I don't believe them to be universal for all cases.
Your management style will dictate how well or if you even should consider working in two roles.
As the team manager, you hold authority over performance and career type decisions for your employees. Wielded incorrectly, the power disparity between you and your employers can ruin your attempts at being part of the development team.
So long as you are aware of that disparity, and you clearly delineate between your roles, I think that you can be both a manager and a developer. I've seen it done successfully a number of times, and I'm currently working on a team in that same situation.
It's worth noting that you can't eliminate all of the effects of the disparity. There will be times when you need to bite your tongue and hold back from a spirited debate. There will be others when you need to pull the trump card and point out that ultimate responsibility for the team lies with you, so you're making a diktat.
You'll need at least two strong, experienced developers on your team who are politically secure. Their role is to keep the power disparity in check and to call you out if things are getting out of balance. You could get by with just one other strong developer, but having a second provides objectivity in case the two of you get deadlocked on an issue.
I honestly like it when my immediate supervisor keeps himself technically relevant. It facilitates their understanding of my difficulties, and I think we end up with a better performing team.