Teams can trade the picks but no comp picks have yet been awarded for this offseason. Its all vaporware until the NFL announces them and that occurs the following offseason. I think they have some play time mechanics that can affect the formula.I don't know, I could see it both ways. Maybe you can't trade a pick that isn't officially yours however you could word a trade that your trading your lowest pick in that round, if you anticipate having multiple picks in that round. At that point I would assume the league would put a freeze on your pick to ensure you have at least one pick to give up.
So while those in the know project us to have two 3rd rounders next year, it won't become offical until next March-ish.