My syntax highligter widget for blogger is available. It’s based on SyntaxHighlighter 1.5.1. Package include all compressed code and brushes, works in blogger mode. This script also handle older/newer posts links. To add it check out this page. For usage information visit this wiki page.
Update: All _WidgetManager magic was removed. It’s simply don’t work for now. Next and previous post don’t use XHR. If you have any javascript errors with _WidgetManager remove this widget and add once again.