YES for some schools -
WVU - during my interview we had lunch w/ 2 D4 students...later we found out during the main presentation that they DO sit on the committee and DO have a say in things, so make sure if you have lunch w/ current students to be friendly, ask questions, and don't let your guard down (etiquette, language, etc)!
OSU - you're interviewed by a current student and professor - don't know if they actually sit on the committee but they do have to report back to them so they have some sway there..
..that's all i know