Just found this on 2ch. Not 100% sure what it is (not super familiar with the inner workings of Japanese television sets) but it looks like some kind of TV listing-detail menu for 00 in which the opening is listed as the new one “Beyond Tears” by Stereopony but “Prototype” is still listed as the ending.
I guess it’d explain why we haven’t heard anything about a new ED yet. Maybe they’re holding off on changing it until all the events it seems to be forshadowing take place? We’ve still got a number of things that haven’t really happened yet (Andrei in flames, Setsuna and those legs, the thing that looks suspiciously like Seravee blowing up, the hole in the sky from what’s probably an elevator drop, etc).

In my mind the new ED for 00 is a bitchin’ montage set to ‘When Doves Cry’ by Prince.
I know I’m sick.
By: Sumeragi Lee Noriega #zomgtripfagcode on 2009/01/06
at 16:33
Well, to be fair, we haven’t seen the second red-haired Innovator make an appearance yet, and the OP has already changed over. Although I guess it would explain why so little info regarding the ED has been released (no radio circulation, no single info, nothing). Setsuna and the legs could possibly allude to his hinted meeting with Ribbons (who was most probably the 0 Gundam’s pilot) in episode 14.
Hmmm. The big Prototype (and Chiaki Ishikawa in general) fan in me rejoices, although a new ED would be nice.
By: fecalresidue on 2009/01/06
at 18:59
It’s weird that the new OP and ED doesn’t come together. I’d guess new ED is spoilery, or the last Ptototype ED would accompany a montage/a very important scene that goes better thematically with Prototype.
By: furato on 2009/01/06
at 22:37
I think maybe they want to keep Prototype for the foreshadowing and use it one final time in the last episode when we see the characters walk off into the sunset, so to speak. Heck if that’s the case, I don’t mind too much if we don’t get a new ED.
By: mangaka-chan on 2009/01/07
at 01:18
You know what, I had a bad image of Marina singing Prototype in my head.
By: mai on 2009/01/09
at 07:25
@mai: I can see them doing something like that–carrying the insert song over as the ED for this week (it’d explain why we haven’t heard anything about a new ED I guess).
By: citrinitas668 on 2009/01/09
at 19:09
oops, I only heard about the new insert song a while ago. That should be it, and it’d be the new ED.
By: mai on 2009/01/10
at 10:09