I'm still wondering why everyone waited a year to rescue him. I mean--A YEAR? Think about that. It's like if your best buddy was kidnapped before the wall street crisis and you only just now got around to rescuing him. I hope they never told Han what date it is, because I'm sure he was just assuming that it was like a week later. Luke in ESB says he'll meet them at Tatooine, it sounded like they were heading there the next day, as soon as Luke got a bit of rest.

The ESB Special-Special-Edition:

Luke: Good luck Lando. I'll meet you at the rendevouz point on Tatooine--in one year.

Lando: Okay Luke! See you in a year. Me and Chewie will just, uh, I dunno, fly around and stuff until then. I hope Leia doesn't care THAT much about Han.

Leia: I don't. That's why I'm staying on this cozy white medical ship for a whole year, even though we already have plans to meet on Tatooine to get Han.

Lando: Boy, the EU is gonna have to invent a whole bunch of shit to explain why we just sat around for a whole year, even when we just said we should meet up on Tatooine to get Han back.