Upgrade iOS using Cydia?

[Tiger7]

I'm on a 3GS with 4.0.1 jailbroken with jailbreakme/comex.

I wanted to know when the 4.1 jailbreak comes out will I be able to upgrade my phone with Cydia? I'll be using limera1n since the other one doesn't support 3GS.

If not then how does the upgrading process work? Will I lose anything?

[lineskis]

You will have to restore then jb with the new exploit

[Antreasthr]

Thankssss