Pau Gasol is a top 15 player in this league. Generally considered a top 5 big man. Is only 30 years old and could easily have 4-5 more years at an All-NBA level.
He is a hugely valuable asset to any team that wants to win in the immediate + short term future.
Orlando isn't going to value a top 15 player towards the end of his prime as much as other teams in the league. The Arenas and Turkoglu deals have crippled their ability to contend for the next few years even with a top 5 player in Dwight.
Pau would be in his mid-30s by the time they cleared the Turkoglu and Arenas salaries off the books.
If the Magic trade Dwight, they need to acquire a younger talent whose value won't depreciate during the dog years ahead and/or unload some of their bad contracts with him.
Thus, I think Bynum is the only Lakers' asset with significant appeal to the Magic, and he's not quite enough to fetch Howard, due to the health concerns.
When you factor in the Orlando fan base's strong aversion to replaying the Shaq scenario and I have a very hard time seeing Orlando dealing Howard to LA.
I do see LA shopping Bynum pretty heavily next season to add athleticism to their frontcourt and shooting to their backcourt. With a strong postseason run (his first), Bynum's value is at its peak and I'm sure the Lakers will be looking to cash in before they consider breaking apart the Kobe-Pau-Odom core that anchored their two titles.
Bynum/Blake for Josh Smith/Kirk Hinrich would be intriguing for both teams.