A president hasn't overturned an ITC decision since the early 90s, IIRC.
Samsung can now use this decision in a court case against Apple to get damages.
FTR for one patent in thousands used in a phone, I think that 2.5% of the phone retail price is not reasonable, it seems a high price to enter a closed FRAND gang who have cross-licensed patents to each other for nearly nothing, whilst setting a high barrier of 2.5% that none of them have had to pay. However if that 2.5% covers all the necessary patents in that FRAND pool, that's potentially a different matter (I still don't think it should be related to the retail price, as that price already covers the licensing of other patents and R&D, etc).
But I don't think Samsung would have gone this route if Apple hadn't sued them so aggressively, so meh.