all the parks need expanding
MK - Fantasy land upgrade was really needed as the majority of the rides are old and people have been on them many times.
Epcot - There are few rides and the only thing that really saves it form being a half a day park are the countrys , but in terms of rides its really lacking. They need to add about 3 rides to the place , perhaps as many as 6 to really get it going.
AK - This is a half a day park if you do it right . We normaly spend just 4 hours at AK and then go back to Magic kingdom for the rest of the night. I'd say it also needs a good 3-6 rides. Don't get me wrong , the animals and the safari are great but many of us live close to zoo's and seein the same things quickly get old.
HS - Your right it needs more stuff most likely it needs the most out of all the parks. I'd say it needs a good 6-10 rides easily . They just need to bite the bullet and make an area of that park.