Projects begin with a 100MB disk quota for downloads (separate from the 100MB quota for source), but requests for more are usually granted. Uploads can be done manually from the web, or in an automated script such as googlecode-upload.py. Once uploaded, files cannot be renamed or deleted, but they can be marked as Deprecated in order to hide them.
Google Code Wikis use a syntax "inspired by" MoinMoin, but the wiki engine is proprietary to Google. All wiki pages are stored in the /wiki/ directory in your project's Subversion repository as files ending in .wiki. So if you don't like the web-based editor you can just use a Subversion client and treat wiki pages like source files in your favorite IDE or text editor.
So what does this have to do with reindeer? The python uploading script mentioned above uses a boundary tag containing the text "Googlecode_boundary_reindeer_flotilla". Apparently Rudolph has secretly been working at the Googleplex for the past few months under the assumed name of "David Anderson".