I don't want to be a spoil-sport, but it's not rocket science to make native bridges really fast, you have to cheat, it's fiddly and different for each OS type.
You gotta admit the native bridge is pretty important though, it could be a bottleneck for all the nice bits native code. On that basis the bridge is fundamental to good performance.
Judging by your comments, I think you should take a look at MoSync 3.0, iPhone/Android/WP7 and supports NativeUI/OGL and everything phonegap/titaniun does plus much more, it comes in two flavors, a JavaScript SDK called 'Reload' and a Hybrid SDK (JavaScript and native C/C++), beats the others hands down. But don't take my word for it, see for yourselves.