@bhogget:
With the one in progress confirmed as AOS4 only, it follows that it is only of interest to committed Red users and developers.
That's such a nice way to put things. "commited Red users". Why the need to make a "red vs. blue" thing out of this again?
Anyone interested in cross-platform development will have to look elsewhere, as this will not be of any use to them.
As you pointed out yourself, GTK has been GPL for ages and has been around for anyone to port. If there where someone doing e.g. an AROS port, would you equally slander the effort?