Just do it. You can always change your mind and revert back if you don't want it (restore a backup). But if you wait and then 5.1 comes out and Apple stops signing 5.0.1, then it's too late until the jailbreak team figures out how to jailbreak 5.1
Sounds like you need a jailbreak then to renew the feeling! But in order to do that you need to find and install whatever it is you wanna do with your device
Btw, if you jailbreak you can always upgrade later on to 5.1 so that is not a problem. But you will most certainly not be able to jailbreak until the dream team comes out with an new jailbreak. But setting your device back to a normal state is the least problem, that you can always do.
But you will not be able to jailbreak with this new jailbreak forever, but rather do it until apple stops signing the 5.0.1, otherwise it's too late. So it's the other way around of what you might think when it comes to the case you where thinking
you make a backup of your iphone (via icloud or itunes) before you jailbreak so if you decide to revert back and un-jailbreak you will just go back to your last saved state (a la system restore/time machine). Not sure how much space jailbreak takes up but it isn't really noticeable if you just jailbreak and do nothing else aside from the fact that it installs cydia on your phone. I'm assuming the amount of space it takes up (with no apps/mods/tweaks) is pretty negligible but I could be wrong.