Yes exactly. Think of it as a windows restore point. Anything installed on your system when the NAND backup is run will be there when the NAND is restored. Anything you installed after the backup, will not.if I were to do another NAND backup, would that back up my IOS's and such to restore my Wii how I have it now, if something were to happen to it?
You can make as many NAND backups as you like. I recommend keeping the first one you made right after installing HBC as well.