about bootmii and updates

hi, i have the lastest version of bootmii ,HBC and DVDx, and some emulator apps (fce gx, VBA gx, wii64 and snesgx), and yesterday i bought NSMB, and it askes me to update (mi wii is 4.0u), i have any risk updating mi wii? because i have read that the update install a new besion of boot2, blocking bootmii. if i update it i will lose bootmii? is safe to upgrade?
Thanks!!

Its perfectly safe. BootMii will be deleted, but it can be easily installed again simply be running the HackMii Installer through HBC. Nothing else will be affected.

thanks, so i dont have risk to brick my wii?

Well, only if you lose power at exactly the wrong moment, which is very unlikely. Just dont play with the power cable during the update, or update during a storm or something. You should be fine, the update takes about 10 seconds from what I've heard, so chances are you won't lose power during those 10 seconds. Anyway, there is no increased risk than someone with a completely "unmodded" Wii running the same update.

thanks!