From speaking with people who've traveled there, foreigners are not specifically targeted for political violence (e.g. no incidents like the bus massacre in Egypt), and the Himalayas are stunning. However, foreigners do get shaken down for the "Maoist tax" as well as by corrupt soldiers, and to get through the countryside you'll need to negotiate through roadblocks. There is also the danger of landmines and of being caught up in a riot.