> A light-weight plug-in electric chainsaw would be pretty awesome.

These already exist, in both plug-in and cordless / battery powered.

Small wimpy ones are widely available. I'd love to have an electric chainsaw that runs on 220v and has a respectably long bar, but those don't seem to be available in the US as far as I can tell.

At 30 amps and 220 volts, that would be about 8 horsepower. I think most motors that size rated for that much continuous power would be rather heavy.