I don't think it's about wanting to get rid of Horry as much as wanting to get Woods, because if Kobe or Shaq gets injured, they basically have no one who can get off their own shot.
I'd like for the Lakers to keep Horry as well, but they need to get another player that can make his own shot in the mix sometime. Shaq is only going to be here for 3 more years I think and you want someone used to the triangle so the Lakers can compete after shaq is gone. Plus Shaq's is really beat up, and unless he losses alot of weight, it'll be hard to avoid foot injuries to due to the stress he puts on his feet.