I heard these items from Apple booth workers who weren't supposed to talk to the press: The DVI output on Mac mini is compatible with newer HDTVs, but the auto-sensing process that mates a display adapter to an HDTV monitor isn't reliable on older models. This may be one of the reasons that Apple isn't hawking Mac mini as an entertainment hub, even though it's just about ideal for that (see a follow-up entry for my case on this).
I also heard that dual-layer DVD drives are running in Apple's labs (surprise), but progress is stalled for the lack of dual-layer burning software for the Mac. Bah. I couldn't swing a blistered foot in Moscone Center without hitting a booth selling dual-layer burners and Mac software to go with. NTI is doing the dual-layer thing with Dragon Burn. LaCie is shipping its dual-layer Mac/PC burner with an updated version of the Lite edition of Toast.
That said, I think it's wise that Apple trails leading-edge optical drive standards until its suppliers naturally evolve their products. The mere existence of internal DVD burners sets Mac notebooks and desktops apart from PCs. In PowerBooks, the internal SuperDrive is sellable as a pure convenience; speed needn't be part of the sell. A new external DVD+-RW/DVD-RAM/dual-layer DVD+R drive goes for about $150, or $90 if you put new raw drives in existing FireWire/USB enclosures as I do.--------