The Kara thing makes perfect sense! Well, as perfect sense as that show makes, since (SPOILER)if Baltar's cylon detector thing was the only accurate way of detecting cylons and he (maybe?) needed a nuke to operate it <i>and</i> it was based off blood, how'd they figure out all the skeletons were cylons? HOWEVER clearly the Earthlons were super advanced if they managed to create this epic downloading system that worked 2000 years into the future etc. Now, if skin jobs are wired the same way as humans then it wouldn't be too much of a leap to assume they figured out how to create a download for humans as well. Now either there are still Earthlons around to build a new Kara, viper and send them back (my guess is they live underground since that's classic post-apocalypse living condition) OR there was some sort of prophet living in the time of avocado buying Tyrol who helped orchestrate the whole final five's hanging out in the future and built a Kara and something to complete the consciousness transfer, possibly something to do with the storm thing. This means there's at least a 50% chance that Dee is coming back due to some sort of restorative property on Earth.
And while that SPOILER was almost entirely speculation, I will bet someone something that at least one of those things ends up being true. *nodnod*