As much as Duchene to Ottawa doesn't work, there is some cold logic behind the madness.
For one, Ottawa has a hard choice with expansion upcoming. Losing Methot for nothing would be pretty ******. Ottawa doesn't have a replacement waiting in wings outside of Chabot. Trading Ceci makes them "expansion proof" since they'll be able to keep Methot, but is also a huge risk to take given the standings.
The holdup so far has been Chabot. Value aside, Ottawa is too ****ed by expansion to consider moving their only potential top-4 guy. Their prospect pool on defense is mediocre at best.
All that being said, I don't think it will be Ceci, he's a RHD (which Col doesn't need) playing 20 minutes a night on a playoff team. If a GM trades a player like that to prevent being lost on expansion that is an all-time ballsy move.
On the other side, it makes sense that White might be available. White is a great prospect, but between Brown, Perron, White, Paul, Chlapik, Dahlen, etc. + draft, Ottawa is pretty deep at forward (especially center) among prospects. Further, Dahlen, Perron, Brown, Chlapik don't ahve the same "profile" as White so they won't have the same type of return.
To top things off, White being unsigned leaves things a bit open. If Dorion has an inkling he won't sign (which almost happened to Ottawa with Gleason) it would be a good use of assets to trade him before he's lost for nothing and hoping to find a replacement with some lesser known prospects.
If, indeed, Ottawa does acquire Duchene, it doesn't make a lot of sense to keep White anyway. Between Duchene, Turris, Brassard, and Pageau, there wouldn't be a lot of room for him if he isn't part of the trade.
Edit: One more wildcard is the potential that Ottawa includes a guy like Andreas Englund in a deal. He's a decent "B" prospect but you never know, Col might fall in love.