I have several 160GB Intel G2s right now. The gap between the G1 and the G2 didn't seem long, but it now seems like ages ago that the G2 came out.
Anyway, the 300GB Intel G3s are supposed to be priced similar to what 160GB G2s are selling for now. No idea on what the 600GB G3s will go for, but rumor has it they will be less expensive than the competition's current 512GB models.