On a localized Iphone (Language set to Hebrew) when we view a webpage using safari and tap on an input field we get the keyboard up with the \"Next/Previous/Done\" buttons i
You seem to be knowledgable, but have you tried creating the UIWebView in Interface Builder, then create a localization on the .xib file?
It seems the right way to go, since the keyboard pops up without app intervention; Cocoa Touch is the one to handle that. I think those extra buttons are not part of the keyboard per se, but added by the WebView.
In your info.plist you can set a value called CFBundleAllowMixedLocalizations, if you check that everything should be translated to the right localized language.