How to partition Time Capsule
I worked this last weekend partition my Time Capsule hard drive. It's kind of a pain in the butt, but it works. To partition the drive, you have to physically remove it. To do this, turn the time capsule over, peel off the the rubber bottom (held on by glue) and remove the screws that hold the bottom housing on. You don't need to remove any screws that have gray rubber around them, these screws hold the hard drive in place. When taking the bottom housing off, be careful not to damage the cable connected to the fan. Once the bottom housing has been removed, simply pull out the hard drive and disconnect the power supply and the the SATA cable.
To then access your hard drive, you need to be able to connect it to your computer. You can buy an SATA to USB cable for about $30. I own another external hard drive, so I removed the hard drive from that and put in the TC hard drive.
After accessing the TC hard drive, you will see 3 partitions. Don't mess with the 2 small partitions. You can add partitions to the main (large) partition in Disk Utilities.
Like I said before, this is kind of a pain, but now that it's done, I'm very happy. I now have a Time Capsule with 6 separate partitions that I can access via Finder.
One more thing, when you mount the hard drive (not in the time capsule) you will notice a folder in the partition call "ShareDocs" (something like that). Add a folder with the same name to every partition you have. Other wise you won't be able to see files you add to the partition before putting it back in the time capsule.
Hope this helps.
Here is an article similar to this:
http://www.appleinsider.com/articles/08/03/06/answers_to_time_capsule_reader_questions.html