Yes, you really should save your SHSH blobs (although, for the iPad, if you've not saved them before, you'll only be able to save 4.3.3). It's a good habit to get into, to save them.
I'm not sure I understand the gist of your post, though. When Apple comes out with the fix to the security leak/jailbreak, you don't have to upgrade to it. In fact, you don't want to upgrade to it, else you'll lose your jailbreak.
And, if you upgrade and you are not the owner of an iPad1 or iPad2 WiFi only, you'll be stuck at the new firmware, back to waiting on someone to jailbreak Apple's newest attempt... For now, only iPad1 and iPad2 WiFi people can use their 4.3.3 SHSH blobs to go back down, should they have to restore.
Ultimately, for those with iPad2 3G, you want to take this week/few days to muck about with your iPad and thrash it hard - figure out what you can/should do with it. Because 4.3.3 is still being signed by Apple, you'll be fine if you have to restore and you'll have lost nothing. But, once they stop signing 4.3.3 and you have to restore, you are out of luck as you'll have to go with the new Apple firmware, which won't be jail break capable (for now).
Biometrix - did that answer your question? If not, try again?
However, I'm glad you asked, cause that gave me a chance to remind the new jailbreakers, with a 3G iPad2 especially, that they want to get all the boo-boos & "ooops, I goofed up" actions out of the way before Apple closes the 4.3.3 jail break window. Cause, if you mess up after that and have to restore - it's back to stock.
Marilyn
P.S. Of course, that's for now - who knows what tomorrow will bring? Regardless of your situation: Back up your SHSH blobs!