AGDI won't be doing it, at least not for free. They're working on a commercial title right now called 'Mage's Initiation', an adventure RPG that calls to mind 'Quest For Glory'.
We at IA don't have any intentions of doing it, currently. We have our hands filled with a lot of stuff. Mostly snacks and beverages.
Magic Mirror games did quite a bit of work on it, and then ran out of steam and time - this often happens with fan projects. People don't realize the amount of work and time that you have to put into them, and things fall apart - everyone loses interest, and then they all wander away to spend their days playing Minesweeper and weeping.
There's currently two other groups pursing a remake of KQ4; one lead by Karen, who did some work on MM games version. She's doing hers with pre-rendered 3D models, and the other is led by a lady who goes by the name of Nightfable - hers is hand-drawn.
I wouldn't expect anything anytime soon.
Bt