http://www.f4forums.com/forums/showthread.php?t=9550
Just so u here it first hand.

Yes 4.6 is cancelled.....

Call was made 2/3 weeks ago due to peoples time being taken on other things. Switch publicly announced he has stopped, so nows the best time to tell u all. Although the last build Switch worked on (5 months ago) is on my ftp And thats the build with some key fixes.
I am going to take a couple of key files from it to give to u guys in the next couple of days.

Why is it canceled

Busy on other things.

Whats the future?.

As has been posted by numerous others recently....Pacience
http://www.f4forums.com/forums/showthread.php?t=9553
Following the announcement : http://www.f4forums.com/forums/showthread.php?t=9550

It was the best ride ever on PC. Too bad development is
now closed on all sides =(. Let us hope that FF or
runaway puppies come up with something in the near future.

Thanks naldo and everyone else who tried to make
OF work.