A quick note. Via foo, I heard rumor that the dual static C4s that are coming in Hyperion were implemented on Sisi. Since I live in a C4, and they cloned the database since I last used Sisi, this was really easy for me to check. I logged in to Sisi and scanned down my system.
There were five sigs in my system. I found our normal static wormhole, which is an X877 (static C4/C4), first. Then radar, gas, radar. I was getting skeptical of this rumor as I scanned the last sig, and it was faint. But, sure enough, the last sig was a wormhole. Faint, so it must be high wspace... and yes, it is an H900 (static C4/ C5).
So, that's a data point for you C4/C4 types: you may be getting C4/C4+C5. Of course, you may be getting some other static. But at least if CCP does C4s the way they did C2s, it's certain. All C2s that have a C4 static also have a highsec static. So I think there's a fair chance that all C4/C4s will go to C4/C4+C5.
Makes me wonder what the other C4s have. But figuring that out would be work. I think I'll read about it. Or I'll just wait for Hyperion.