Just an aside, look for more sealed transmissions in the future. And it's not so the dealer can make more money on fluid changes, rather it's because of people putting the wrong fluid in their transmission.
I was heading north a few years ago with a buddy and I saw I needed to add a bit of transmission fluid to my Ford because of a recent flush and fill. So I grab a bottle of Dexron/Mercon. He looks at me and exclaims "I thought all Fords used Type F"! I told him that wasn't the case. Interestingly, his Ford had lost its transmission a year earlier, for which he blamed Ford - naturally.
Each transmission uses glue to bond the friction material in the clutch packs. The glue is usually only compatible with the transmission fluid specified by the manufacturer. Use the wrong fluid and it could weaken the glue and there goes your transmission.
So the solution, from a manufacturers perspective with regard to warranty cost is to seal the transmission. Of course they're not really sealed, you just need to fill them from the bottom of the transmission pan using a special adapter and a somewhat lengthy procedure to determine when the fluid level is correct.
