I searched the forum and was surprised this hasn't been mentioned. Steve Gibson, a computer/security guru, and Leo Laporte (of TechTV fame), have a weekly podcast called Security Now. They go over security news and introduce beginners to concepts like certificate signing, cryptography, and fundamentals of the internet and computing. There's a 6 or 7 episode series in which they "build" a computer by explaining how it works from the ground up. Starting with transistors and then going to logic gates and then on to the stack and operating systems. Now that we're not gonna have our Pi until next year, I think this might help some pass the time and learn something new.
That's the page where the archive of the podcast is hosted. Episode #233 is the start of the "Let's build a computer" series. There's a host of other topics some here might be interested in also on that page. Steve is the real deal. He coined the word "spyware" back in the day. He has a host of free utilities on his corporation website, such as Shields up, to test your open ports on your machine, and also a high entropy random number generator, for making those perfect passwords. The only thing not free on his site is Spinrite, a hard drive recovery and maintenance utility that he wrote in assembly!
Check it out if you wanna. It's highly informative, and maybe learning something will help pass the time until we can hold the Pi in our hands