i looked at the code and i think there is the possibility to improve the load-behavior of the scripts.
The adding of scripts is momentary done in the constructor of SyntaxHighlighter. If its done in (i think) "shortcode_callback" it should only loads on the sites that really use the syntaxhighlighting feature.
It also would be nice to have an option to choose the brushes that are really needed (i for myself only use the php-brush).
I know, so many wishes and so less time ;-). If you need any help, feel free to ask.