I doubt we'll see a bump in power for the 4-cylinder at all from the 160HP variant. It's still competitive with the other market 4-cylinders, and people who buy the 4-cylinder versions want economy over anything else. Horsepower ruins that economy.
That being said, the V6 might see a big infusion of power.
Actually, when Honda recently announced their new
Advanced VTEC valvetrain we will see improvements in I-4 engine power and fuel economy. My guess is that the new 2.4-liter I-4 for the 2008 Accord will use
Advanced VTEC, rated at around 185 bhp (SAE 08/04 net) and 5-7% better fuel economy than the current engine. With more "sport" oriented engine timing 220 bhp from a 2.4-liter I-4 engine could be within reach.