So far I haven't seen any website mention what the pick protection is on the Memphis pick we are receiving. I did see one tiny mention on ESPN that says we'll get the Memphis pick 2 years after Memphis gives their pick to Denver. Memphis owes Denver their pick. Here's the protection on that:
2015 first round draft pick to Denver
Memphis' 1st round pick to Denver (via Cleveland) protected for selections 1-5 and 15-30 in 2015, 1-5 and 15-30 in 2016, 1-5 in 2017 and 1-5 in 2018 and unprotected in 2019 [Cleveland-Memphis, 1/22/2013; Cleveland-Denver, 1/7/2015]
So according to that tiny blurb I saw on ESPN, depending on when Memphis gives up their 1st to Denver, Boston gets Memphis' pick two years later. Unfortunately, it didn't clarify if there were protections on it for us.