I've been digging all day, and nobody is really willing to tell me exactly what is going on. It's not a situation that anyone is really speaking about internally, but from what I have heard, Smith and Lafontaine had issues with each other. Once Smith was let go of this morning, Lafontaine held himself accountable and stepped down himself. That is the story I am getting right now, but it's too early to confirm such thing. I will continue looking into it...
As for Garth Snow....there has to be someone else out there who is a better replacement. On XM today (if you don't have XM, check it out, it's great), they were discussing how Pat Quinn maybe would have been a good replacement. Compared to Garth Snow, I would have been a good replacement. I like Smith's offseason moves, and when I first heard of the firing early this morning, I wondered whether not signing Mike Peca was part of it (NYI offered Peca a three year deal worth quite a lot of money).
More as it develops...