I don't think it would be a catastrophe if we failed to make a move. We're playing very well right now.
I doubt that happens though. Yzerman tends to tinker at every TDL. Last year, we all knew we needed a D, but none of us saw the Coburn deal coming. The Connolly deal, or, more specifically, the timing of it, is probably one of the most debatable things Yzerman's ever done.
This year, our wish list is pretty much the same. At the top, we need a D, probably a righty. But it turns out those aren't easy to acquire.
I'm not sure who we'd move out. That's an even trickier question. Drouin is obviously on the block. Would we deal Condra in the first year of his deal? He likely doesn't have enough value to bring back anything to help us in the playoffs anyway. Can't see Killorn moving. I think the franchise likes him a lot, especially in the playoffs. I still wonder about Namestnikov. His value has spiked upward recently, which is the exact time Yzerman tends to deal a guy (if he ever was planning to deal him, which might not be the case)...