After thinking about this idea long and hard all day, I would definitely do it.
Gasol is a better player, and a better fit. He could put us back on the map this year, and it´s much easier to find an adequate PG than a Center. If we assume we can´t get anything of value for the big three, then Rondo´s our most valuable trade chip, but there´s not much interest in his services around the league, apparently. If we decide to blow it up after this year, Gasol could get us the pieces we can´t get for Rondo.
The more I think about it, the more I like it (except the whole "trading with the purples" thingy, of course). Yes, I think this is a slam dunk, as Chris put it.