I don't have any information on that. Based on what I've seen posted, I assume the desire is for it eventually to be updated for RMU as with other material from previous editions of RM, but I haven't seen any hint that a new Arcane Companion has an author yet, much less a plan of attack. I also don't know about the copyright status, i.e. is ICE able to freely update and revise the material from the old Arcane Companion or would a fresh start be required?
My personal opinion is that there are parts of it that work very well, e.g. I like the Node aspects. (Next month's installment in TGC builds on that in fact.) And there are other parts that I think are just too similar to lists from the three realms. I am interested to hear what other people think, though. Do you like where I'm going with this? Did you prefer it exactly as it existed before? Assume that by the time it reached a companion, the lists would be properly sorted into open, closed, and base lists, with associated professions.