so what now with this pick? are we guaranteed to get just the one?
The trade on draft night was for a Clippers pick, not Memphis.
Here's how the two picks work:
2019 first round draft pick from L.A. Clippers
If at least two years after the L.A. Clippers conveyed a 1st round pick to Toronto, then the L.A. Clippers' 1st round pick to Boston (via Memphis) protected for selections 1-14 in 2019 and 1-14 in 2020; if the L.A. Clippers have not conveyed a 1st round pick to Boston by 2020, then the L.A. Clippers will instead convey their 2022 2nd round pick to Boston [L.A. Clippers-Memphis, 2/18/2016; Boston-Memphis, 6/23/2016]
2019 first round draft pick from Memphis
Memphis' 1st round pick to Boston protected for selections 1-8 in 2019 (conveyable if Memphis conveys a 1st round pick to Denver in 2017) and 1-6 in 2020 (conveyable if Memphis has conveyed a 1st round pick to Denver by 2018) and unprotected in 2021 [Boston-Memphis-New Orleans, 1/12/2015]
http://basketball.realgm.com/nba/draft/future_drafts/detailed