Ok, this is a biggie to me.
I have two series up right now, with a third going up in two weeks. Two of those series are collaborations that I am doing the writing on, but other people are doing the art.
On Comic Fury, when I set a series up, I can then add (or delete) other creators, and give them full permissions to make changes on the back end, and it shows up on either of our profiles.
This is not that difficult to do, in other words. I am all about making sure that my co-creators get the proper credit, and while neither of the artists I am working with are on Tapastic, I want to be able to share access to the comic with them if they ever do get an account here (and with one of them, that is highly likely).
So no, it's not going to make or break the site, but being friendly to collaborations is something that is important, as I feel that they are going to become more common as the webcomic medium matures, and people start banding together to bring their visions to life.
Eagle
(And there are several more series behind those three)