As Zaxo/Brooks mentioned, a significant part of the role of manager is dealing with crap like office politics, budgets, etc.--something that most developers don't want to deal with. I know if I were your current boss, I'd rather focus on architecture and development.

It is important, though, that whoever takes on this managerial role is sufficiently technical to grasp the issues the developers are dealing with. At my last company we had someone like this, and it worked great. She knew her stuff, but didn't want to be a developer. Developers could talk to her straight about why such-and-such was taking longer than expected, and she got it (often suggesting better alternatives). She was great at deflecting all the office crap and letting her team focus on writing software. The developers respected her, so when she had to bring down the hammer and say that something had to be done this way for whatever business reason, they had an easier time accepting that.

If your company is going to bring someone in, I would suggest that as part of the interview process, you and some of your team get to interview him/her, to make sure they've got the technical chops.

Brad