The main reason why I'd be interested in seeing an animated B5 would be for the ability to see truly alien characters in truly alien settings. It seemed to me when reading the original series outline in the script books that Delenn remained far more Minbari in that than she ended up in the series. I'd have enjoyed seeing more of the crystaline structures of Minbar, too.
My main reason for not being interested is because much of what made B5 special was the subtlety of some of the performances even without words. I'm not sure that the power of Londo watching the bombardment of Narn would be able to be carried over into animation.