I think I'd consider Good Skepticism openess to being proved wrong, more than anything else. But then again, I'd consider a good believer someone open to being proved wrong, too, so what's sauce for the goose...
Now, I'm pretty argumentative, (try to hide your shock, people) and I don't really think there's a Bigfoot out there, but...thing is, what aggravates me really isn't people-who-think-there's-a-Bigfoot so much as sloppy thinking. It's the goddamn sloppy thinking that kills me and makes me froth. (I suspect I'm not alone in this.)
I suspect with Footers vs. Skeptics, the frustration on the skeptic side is probably half the time just about the damn sloppy thinking on some of the Footers side--you know, the acceptance of tracks by somebody known to have faked other tracks, the blobsquatches, the claims that the PNW is a dense and untrackable wilderness,...the sheer absurdity of some of the claims (do I need to mention the testicle prints?)...it just adds up and it becomes not so much that about whether there's a Bigfoot as about wanting to grab the Footer in question and beat critical thinking skills into their skull with a blunt object.
Nevertheless, I don't know any skeptics who, when a Bigfoot corpse was hauled out and dumped at their feet, wouldn't go "Huh! Well, shows what I know. Cool! Somebody get me the bonesaw and the camera!"*
So in that regard, yeah, it's akin to fence-sitting, in that a skeptic knows everything is subject to more data. But I suppose the skeptical position on Bigfoot would be something like "There is no current evidence that I consider convincing, and many valid arguments for why there probably isn't one." But of course, when the current evidence changes, this position is also subject to change.
Fence sitting, on the other hand, strikes me as more "I don't know if there's a sasquatch." So I think there's a difference, even if it's just the difference between "I don't know," and "I don't know, but at the current time, given all available evidence, I consider it highly unlikely."
*Okay, not all of us would go for the bonesaw....