I found this new beach cruiser for $599 (including shipping) that features a NuVinci hub. Light bike weight is not an attribute of cruisers so the NuVinci's heft is not as critical. Many cruisers don't feature more than a few gears, many are single speed, so the NuVinci should be an improvement I suppose:

http://www.abikestore.com/Merchant2/...Store_Code=cbs

It's new technology so it can improve over time. I'm sure weight will drop and performance will rise.