Depends on how much snow (well really salt is the issue) you plan to plow through. If you're walking around dusting it really should be an issue. If you go through ankle deep stuff I'd treat your boots more. I hear good things about Obenauf's and will try them soon. I've used SnoSeal the past few years and they work well.
They salt pretty liberally here in NYC so Alden's Leather Defender alone won't cut it.
Thanks SuitedDx. I'm in Toronto, and there is a ton of salt on the sidewalks during winter. Not that I would take them out in a snow storm, but after the fact, the salty puddles can definitely do some damage.
In regards to Obenauf's, there is some interesting discussion here against using it. I've used it on a few pairs of cheaper boots and haven't noticed any ill effects.