Just because you get a notification of a FW update does NOT mean it must be immediately installed. Allow some people who did not read this post to install it first to see if they had issues.
I suggest you start with at least a 50% charge to be on the safe side as it will probably consumed quite a bit of battery and 50% is a good safety figure.
Before applying the update I suggest you do a hard reset just to be certain nothing is interfering with the update during the install process. (hard reset instructions in my signature links)
It would also be a good idea to use the App Backup to make a full backup of your system's apps and associated data/settings just in case something does go wrong.
If you are rooted and/or have any custom roms installed I would take a hard look at even thinking about ICS/JB or other patches unless you first put your TF back to stock.
One more thing that may end up being important. Manually check your Android Market app and Amazon Market app for updates just prior to applying the FW update.