I respect your decision from both sides of the fence... That being said, if you don't go this weekend, at least go try your bike out on a day trip (this weekend) on a shorter ride. If it rains and you get soaked, see how the gear holds up, and how you are feeling. At some point, you have to commit yourself to the wind and jump into things. You will get poured upon at some point. That's a part of the adventure. Perhaps you could even start the trip and turn back if things get bad, or if things go good, bet the farm and go for the camp ground. Good luck!
Edit- re-reading this, it looks like mud is the big concern. So, the good news, is that if it raining hard enough, it washes off the mud!
