Yeah, I'm not quite sure what the end-game of that was and at times it seems like the characters only know as much as the audience knows -that Gordon is dead. I mean, otherwise, why would Batman stake-out the Gordon household and take the abuse from his "widow" and look so beaten up over it? Wasn't this his plan?!
To be honest I was kinda disappointed that it WAS just a ruse. For a minute there it really felt like Nolan was doing something bold and unexpected by killing off such an established character, and it really made me sit up and think "holy shit, anything can happen in this movie now!"
The reveal that Gordon was the one driving the truck was certainly a good one, but I also can't help but be a bit disappointed that Nolan didn't try to shake things up more than he did.
I'd actually read shortly before seeing the movie that Gary Oldman wanted out of his contract. So I was prepared to believe that Gordon was dead, comic continuity or significance bedammned. I thought the whole sequence worked really well.
In hindsight, I've wondered if the story about Oldman, who as we know is back for TDKR, was planted by the movie-makers to fool people like me.