n00b help updating from 3.2E

Hello everyone...I haven't been using my wii that much lately and now that the 4.0 update has been released I've been wondering how much longer I can stay on my current system version.

It's not that I need the new SD card features but what bugs me is the fact that games such as animal crossing aren't working on my Wii...now it's not animal crossing that I really care that much about, it's any future games that might come along, not being able to access the shop channel is also a bit frustrating...I would have already updated to newer versions but the problem is that I have the homebrew channel, some wiiware game wads and most importantly, old game saves from games such as super mario galaxy, super smash bros brawl, metroid etc...some of these are NTSC region games...so I want to know if there is a safe way to update my wii without loosing all my save games or any other functionality...since every newer wii update states that old saves will be erased I don't want to risk it...I have a day one Wii with the wiikey chip

thanks in advance :)

1. Updates don't erase saves
2. WADs are piracy
3. You can skip disc updates with Gecko OS