I guess an electric snowmobile would be quieter and have less maintenance, but I guarantee you the greenies would still be complaining that we are destroying the environment, the same skiers, snowboarders, snowshoers, etc. would still want to close riding areas because we’re using their forest and we’re in their way, and the list goes on and on. So I don’t think it would be end all.
There are extremists who would prefer to declare everything Wilderness, but they're in the minority. Most backcountry skiers I know are perfectly willing to share terrain, even if we'd all rather have acres upon acres of private powder to enjoy (let's face it, who wouldn't?).
The noise impact of someone on a two-stroke with an aftermarket can doing laps is huge, and the noise footprint often extends well beyond riding areas into neighboring non-motorized areas (with the low noise floor in the mountains, sound carries and all that, at least when the wind isn't loud enough to drown it out). The noise and smell of a two-stroke are serious turn-offs, particularly for those without a motorized recreation background.
My educated guess, as a skier, is that electric sleds would not only reduce the user conflict potential substantially (see also the Beartooth Pass/Gardiner Headwall discussion that the Winter Wildlands Alliance pushed last year), but also make skiers and snowboarders more likely to consider buying sleds for backcountry access. If that happens, you (a) have more people supporting the sled industry, and (b) have a lot of people whose primary interest in backcountry recreation is non-motorized who are suddenly a lot more sympathetic to motorized access.
Re: the pollution questions, yes, building the batteries (and the rest of the sled) is still a nasty process, as is extracting and refining petroleum. In Montana, we'd still be polluting plenty, because the electricity recharging the sled would probably come from a coal-fired plant...but on a global scale, it's a lot easier to address pollution at a smaller number of large-scale point sources than to address it on a much, much higher number of much smaller (and more mobile) point sources.
Personally, I'm looking forward to electric vehicles (particularly motos and sleds) becoming more widespread. I'd rather not reek of two-stroke and have oil splatters all over my jacket, and fewer moving parts sounds like a damn good thing to me. Yes, the recharging issue is still a damned big one, especially for playing in the mountains, and probably even in-town in Cooke (I doubt the electrical grid there would stand up to the challenge if every sled in town on a busy weekend was being recharged overnight). But the advantages—minimal direct pollution (noise and exhaust), fewer moving parts, instant torque—are huge, particularly when we reach the point where the range and recharging issues and sufficiently mitigated (I don't think "solve" is the right word, but if we can reach the point of being able to have all-day range and a substantial partial recharge in the time it takes to buy and eat a burger, we'd be in the same real-world ballpark as today's sleds and bikes).
