Renee mentioned on Twitter that she expects to be back at the end of this month. Thing is she said the same thing back in Oct/Nov. Interesting bit that they hired Kalyna to do only traffic and not the live center, so if Renee comes back, they'll have 5 people on the morning news. Too much, considering they're not winning the time slots.
As for Marie, hard to say what the deal is with her situation. I do remember reading that the tree hit her basically square in the head (something like you would see in the cartoons, if you can imagine it), which led to her vertebrae being squashed. With those types of injuries, she's going to have permanent damage... sad to say. Will she be able to one day come back and work in the same capacity? who knows, but like you said, both sides are screwed. And clearly they moved on from her since they hired a replacement that basically looks like a younger Marie Coronel... Mimi Elkhalla.