If I understand you correctly, it'll be the same deal as always. The new apps will require a firmware update of your iPod or iPhone. The firmware update process will re-lock it and delete things like Installer.app. Most likely it will also disable whatever method is currently being used for jailbreaking. Some enterprising hacker will come up with a new method, though. So you'll end up restoring your iPod with the new firmware, and then jailbreaking it again and re-installing your apps. And you'll have to wait, almost certainly, till the new jailbreaking software comes out after the official release of the firmware....