I know, Dwight only wants to play for the Brooklyn Nets. But if I'm the Magic, getting Brooke Lopez and Kris Humphries for Howard is just not all that exciting.
With Nash on board, it makes sense for the Lakers to press the issue on Howard. You have to figure given the ages of Kobe/Nash, the window is very tight (2 years perhaps?) to bring a championship to LA with this current roster. Trading Bynum (and whatever else you need to throw in) for Howard would easily make the Lakers one of the favorites in the West (if not the favorite). Gasol would be the only player the Lakers would have to think twice about including in a deal with Bynum, but I think you do it to get Howard.
If Kobe/Nash can convince Howard to love LA (you just have to complete the trade before Howard changes his mind yet again!), the Lakers would be really tough.