Answer from BigFoot regarding V8: It's for Webkit's 'JavaScriptCore'. OWB does not, and will not, use V8. V8 is a Chrome thing, not a Webkit thing.
Yes I asked Fab about his plans regarding the Blink engine not long ago and he said he would be staying with Webkit for Odyssey.
That pretty much confirmed no V8 for Odyssey, but back then V8 was for Webkit as Blink had not been forked at that point.
The TenFourFox PPC browser has a JIT and work is underway to port it to Leopard-Webkit.
https://code.google.com/p/leopard-webkit/