SuperDrive is a $100 BTO option on the AppleStore, so it IS possible to burn DVDs on Mac mini.
But you're right, the $599 Mac mini SHOULD have a SuperDrive built-in (a huge mistake from Apple's part, as I'm sure lots of customers would pick up the $599 over the $499), as I'm not sure that a 80GB HD over 40GB or 1.4GHz over 1.2GHz is really worth the $100 dollar difference.
Another mistake is the skimpy 32MB Radeon 9200, a 64MB Radeon 9700 would give the Mac mini a game-console appeal AND leverage Tiger's forthcoming ImageCore and VideoCore features (Radeon 9200 is underspecced for those components), surely a case of Apple's fear that Mac mini would cannibalize the iMac G5.
To anxious to please the stock-market, Apple would nevertheless benefit in the long run as Mac mini could be picked up in the 10s of millions, as I'm sure that a beefier Mac mini would definitely give a much needed "Halo" effect.
I love the form factor and the whole philosophy of the Mac mini, but the first incarnation is a bit short in the tooth. Same could be said with iMac G5, Geforce 5200 Ultra is frickin' TWO YEARS OLD!
I'm waiting for stronger GPUs before shelling out for either Mac mini or iMac G5.
At least worth 4 cents...
One Week Later: Mac Mini Still A Good Thing?