I would love some feedback from the group on this one, as well. I am on my second TJ and it has been rained it several times without problems. However, I am a little paranoid about that issue, too.
I usually try to keep a towel/plastic in the jeep with me for this reason--and drape it across the dash to keep the majority of a heavy rain from going directly into the dash. I know it won't keep it all out, but helps somewhat.
From what I have read/been told previously, as long as it is not submerged in water--it does okay. I don't spray down the dash when I hose mine out, but it is built to withstand some moisture.
Thoughts from the "more seasoned" Jeepers?