The bridge (as bundled in the hotfix) contains
everything you need to ensure your jailbreak is fully up to date.
(Whether that is required... well, as knc1 said, making sure the bridge is up-to-date can't hurt, even if it turns out you were already up-to-date anyway.
)
Do not bother installing or updating any hacks e.g. usbnet before updating, since firmware updates will wipe them out anyway and you will have to reinstall them after the update regardless.