I received my new (old) G4 Cube a few days ago, and after a false start with some bad memory (the seller sent me a partial refund to cover new RAM), it's up and running. To move the site from the old Sun Ultra 1 to the Cube was absolutely simple, and literally took about 10 minutes:

• Create a "website" account on the Cube
• Copy my latest site backup to the website account and expand it
• Update my wiki and weblog engines' configuration files
• Copy some Apache config from the Sun
• put cron entries in for my semi-dynamic content (such as SpringViz Downloads)
• Change the port mappings on my router.

I will have to take the site down for a bit when the RAM comes in, at which point I'll install the RAM and put the box into its final resting place on my "rack".