Extremely unlikely. iPhone prices drop because Apple gets good profits from the contract kickback, plus the phones are subsidized by AT&T. That model doesn't fit the iPad.
Existing iPod Touch prices drop very little when a new model comes out. IMHO, the Touch model is closer to what will happen to the first gen iPad. At the most, I could see a $100 drop but I wouldn't be surprised to see less. Apple could even keep the old model at the current price and charge more for the iPad 2.