The amount of space it takes up is really pretty minimal over IE6, and at least so far, it seems to be living up to the enhanced security claim. It's the only version of IE that wasn't in need of security patching in the latest monthly batch from Microsoft.

If you're short on disk space, there are better places to look for freeing some of that up... Or, with Christmas rapidly approaching, there's going to be good deals on that sort of thing every week until Christmas. You could just pick yourself up another drive, and use it for additional storage.