The only sport that receives a major grip from me is beach volleyball I believe the sport to be a joke, and the celebrity given to it is insupportable. Beach volleyball is a hobby sport that is nice in local tournaments and whatnot, to support it on an Olympic level, when there already is a perfectly good collegiate volleyball event, is unnecessary.
All other sports I am more or less okay with. I am miffed they are getting rid of baseball, only because baseball is just as valid as any of the other team sports. You have to have soccer and basketball, they are fine, though I dislike that they pool from professional athletes. Badminton, race-walking, and all those other sports are only pointed out because they are not popular, but they are in fact sports, extremely athletic, and valid. Badminton is a hell of a time if you actually play it. I believe that BMX has a perfectly applicable place in the Olympics, as it reflects a modern discipline of cycling. Just because something is new and innovative does not mean it is not a valid sport. I actually believe that skateboarding would be perfectly okay, as would inline skating. Skateboarding is almost the summer version of snowboarding, and inline is likewise for figure skating.
Some of the sports I would like to see added, in order of importance:
Pankration - The Game of All Powers has been long absent from the Olympiad. It's ancient nature would lend it's modern incarnation to being mixed martial arts, i.e. UFC. Now, it is understandable the trepidation surrounding this sport, especially in the Olympic arena where even boxing goes by amateur rules and not professional, but there is a definite potential for adaptation here, and I would love to, and in fact expect it to be seen given a look-over in the next few Olympiad. (MMA as a socially-accepted sport has only been around for two, or arguably only one summer cycle).
Kickboxing (Possible distinction as 'Muay Thai') - If Pankration does not fly, which I doubt it will, kickboxing must have it's day. If such specialized time-relative combatives such as Tae-Kwon-Do and Judo can have their place, general kickboxing (or Muay Thai, even) should as well. The facility is already there: The boxing ring. Kickboxing as a sport is huge around the world, and they are left out while boxers have all the opportunity.
Cricket - I do not know why this isn't a sport, honestly, how huge it is around the world. It just seems like one of those 'duh' inclusions. It has already been a sport, but experienced only one Olympiad.
Climbing - Another perfectly Olympic-level sport that is neglected is rock climbing. I think it should be given a run as at least a demonstration sport one cycle.