should i back-up or not

[360psp]

I have an ipod touch 2nd gen jailbroken firmware 2.2.1.
I was wondering when 3.0 comes out and i upgrade to it normally what will i lose? I know iam going to lose cydia and any other app from cydia but apps from ********** will i lose them or will they remain on my springboard. Or is everything on my ipod including music and others be erased and i would have to restart over?

[blkcadi]

When you upgrade you can restore, then everything you had on your pod. Cydia apps will have to be re-installed if you jailbreak again.