As others have noted, the key points to keep in mind are whether the features of the second generation iPad are worth $120 difference to you.
Beyond that, you'll probably save a bit more in terms of resale value by choosing the iPad 1. Its price is unlikely to drop more than $100 more, maybe less. The iPad 2 may go down a bit more than that.
So, figure you're saving, say, $150 by purchasing the iPad 1. Is that savings worth it?