Is the regenerative electric bicycle 'green' or another excuse to be lazy?

Thanks to the brilliant minds at Sanyo there is now a product that challenges two of the biggest competing movements out there: fitness and being 'green' with the regenerative lithium-ion bicycle. Just introduced for the Japanese market is this electric bicycle from Sanyo. I've seen electric bikes before that are a bit of a crossover between traditional bikes and mopeds, but this opens up a whole new bag of chips.

The bike has a regenerative braking system. It operates like a traditional electric-assist bike, but when brakes are applying a motor uses the dispensed energy to recharge its lithium-ion battery.

Via Green Car Congress

This just seems like a two steps forward and one step backwards type of an upgrade. Overall, the bike has maximized its green capabilities, so putting a regenerative braking system on one is a bit overkill. And it may increases laziness on the rider's part.

The system extends the distance the bicycle can travel on one charge to 50 km from 35 km for existing models.

Squeezing the left brake lever on the handle turns a 250 W motor on the front wheel into a power generator that charges the 4.0Ah-25.9V lithium-ion battery.

The bike can be put in a mode in which electric assistance is not used on level ground and the brakes are automatically applied, with regen, when going down a slope.

The lithium-ion battery is 760 grams lighter than the conventional nickel-hydrogen batteries used for such bikes. Sanyo is targeting sales of 10,000 units of this bike per year. In 2007, more than 280,000 electric bikes were sold in Japan; a 106% increase over the prior year.

Not sure what the weight of the bike will be, but you can bet that it is not light...