Nope. They're doing really well right now, but they are still the Cubs. They've started great before and caved at the end of the season, so don't get your hopes up just yet.
I'm a huge fan, but haven't had any time to check out their stats, I know they're doin' fine (so far). But, yeah, they are the Cubs. It's pretty much all downhill after a bit. But being a fan, you learn to live with it and cope.