If it is large enough for it's gravity to capture a moon then it is a planet.
It isn't the Planet X people were imagining past Neptune, but it is a planet.
The fact that it has another piece of matter revolving around its gravitational pull doesn't make it a planet.
If Kate Moss was hovering in Space outside the distance of Pluto, she could have a very fattening keylme pie revolving around her but she'd still be moving around the Sun and I wouldn't call her a planet.
She's not a planet. She's a STAR, yes ...
Pluto is midget wrestling. Interesting, but nobody at NASA is aiming any missions that direction.
Planet needs to have a singular influence in size, interest and solar system fun ... ness ... to warrant our care.
The outer gas giants annoy us enough. OK Neptune ... you are a coagulation of ammonia and sulferous and nitrous oxide .... We're not going to make a movie about you housing a tribe of beautiful women wearing swimsuit uniforms and sporting perfectly cone shaped breasts.