So here's my theory on Luke's saber showing up in Ep. VII:

As we know, Luke loses his saber and hand on Bespin. They end up caught in something similar to what caught Luke, and don't fall all the way to the planet core. An employee of Bespin finds them and reports it to Lando. Lando stores the saber for safekeeping while Luke is hiding out and training with Yoda. While training, Luke crafts a new saber.

Fast-forward to the Battle of Endor. Lando heads that way in the Falcon with the saber stored in the ship, ready to give it back to Luke. But Lando sees that Luke already has a new saber, so he doesn't give Luke's original back to him, maybe hoping to sell it for a profit (he is a scoundrel, after all). Lando is the last person we see flying the Falcon in the OT.

Fast-forward to the Battle of Jakku. Lando is there in the Falcon again, since this is (apparently) a pretty major action in the continuing war. He has since either forgotten about the saber stored on the Falcon or just stores it in there to keep it close. The Falcon crash-lands on Jakku and Lando and crew have to abandon ship pretty quickly (maybe still under fire from the Empire). The saber sits in the Falcon, forgotten, until Rey (a junker on the planet Jakku) stumbles across the wreckage of the Falcon and finds the saber. Coincidentally, Han and Chewie find the Falcon at the same time, recognize the saber in Rey's hand, and want to return it to its rightful owner (Luke).

So there you go. A more realistic way (at least more realistic than the saber falling through the freakin' atmosphere) for Luke's lightsaber to end up on a different planet to kick off the new trilogy.

Luke's saber went falling through the same ventilation system/air tunnels/waste disposal tubes that Luke went falling through. You'll see that they have all kinds of tubes, chambers, doors, etc. The lore written about that part of Cloud City indicates that there are access hatches and walkways and whatnot strung throughout them for maintenance purposes.

Most likely scenario then is that it got caught up in the system, an Ugnaught found it, didn't know what it was, tossed it in a scrap pile and sold to some junk dealer that then offloaded the scrap on Jakku.

Luke's saber went falling through the same ventilation system/air tunnels/waste disposal tubes that Luke went falling through. You'll see that they have all kinds of tubes, chambers, doors, etc. The lore written about that part of Cloud City indicates that there are access hatches and walkways and whatnot strung throughout them for maintenance purposes.

Most likely scenario then is that it got caught up in the system, an Ugnaught found it, didn't know what it was, tossed it in a scrap pile and sold to some junk dealer that then offloaded the scrap on Jakku.

That's a possibility, although I think it would be a bit too coincidental.

I tried to take into account what we know so far about Episode VII:

• The planet is named Jakku, over which apparently there was a huge battle between the Rebellion and the Empire.
• The last known person to pilot the Falcon was Lando, who was also owner/operator of Bespin.
• Bespin was where Luke lost the saber.
• Rey salvages scraps from the hulks left over from the Battle of Jakku.

After that, it's all speculation:

• Lando and the Falcon would likely be at the Battle of Jakku.
• Lando found or was given the saber on Bespin.
• Lando kept the saber with him.
• Lando lost the saber or was forced to leave the saber in the Falcon.
• Rey finds the Falcon and the saber.
• Han and Chewie find Rey when looking for the Falcon.

Edit: And I realize that my scenario is no less coincidental.

You assume Lando keeps the Falcon and doesn't give it back to Han. Not sure why you would assume that.

Also you assume that Lando returned to Cloud City. Remember while Luke was losing his hand and saber Lando was getting the hell out of dodge. And I seriously doubt Han let Lando keep the Falcon. Letting Lando use it for one battle where Han would have no use for it is much different then letting him keep it..

Are we certain the saber scene is at Jakku???

I'm not sure why it's an issue. Someone went dumpster diving in Cloud City. I mean, it happened in the EU.

You assume Lando keeps the Falcon and doesn't give it back to Han. Not sure why you would assume that.

Yea this is not believable.

Y'know...Luke could have simply made another saber identical to his father's...

"Hey, y'know, this was a pretty effective saber design, and it is good for beginners, so I'm going to make it and give it as a gift."

As far as we know, Luke has only seen two lightsaber designs - Obi-Wan's, which his RoTJ saber is modeled after, and Anakin's, which he used from Episode IV to V and what Vader's saber is based on. Maybe Luke just isn't that creative of a guy. Or maybe, because he's giving it to a family member, he chooses to honor Anakin by basing the saber on his design.

Y'know...Luke could have simply made another saber identical to his father's...

"Hey, y'know, this was a pretty effective saber design, and it is good for beginners, so I'm going to make it and give it as a gift."

As far as we know, Luke has only seen two lightsaber designs - Obi-Wan's, which his RoTJ saber is modeled after, and Anakin's, which he used from Episode IV to V and what Vader's saber is based on. Maybe Luke just isn't that creative of a guy. Or maybe, because he's giving it to a family member, he chooses to honor Anakin by basing the saber on his design.

Funny. It's actually not practical whatsoever. IT's very unwieldy, the box is in a terrible spot, and those window wipers glued to the bottom half cannot be comfortable to hold.

Heir to the Jedi - the new novel with Luke based between Ep 4 & Ep5 - it's canon (as all the new books are) and might address a little bit of these topics. (meh overall as a novel and story but I'm reading them all for the tiny little easter eggs that seem to be put in there)

Also - agree that thinking Lando got anywhere near Bespin after taking off in the Falcon is lunacy. There was a garrison there at that point - the Empire totally took over