I like the Aluminium enclosure, I think it's alot better than what they used to have and what most PC's out there still have, namely no design at all.
I would like it to be more silent. And with the Intel chips coming, they could loose some fans inside and make the beast just that, a little more silent.
I do think however that the overall design won't change much. Since the design they have is optimised to give the best possible airflow over all the computer components inside.
I'd like more USB ports and Firewire ports on front and back, I'm just barely managing at the moment. But one more and I'm in trouble.
More internal HD room, a total of 4 will do. An extra optical drive would be nice.
And I would like to see BT/AP become standard. You'd be suprised how many people opt for this option on the current models.
In all likelihood they'll fit 1GB of Ram in the two top models and fit 512MB Ram in the basic model. I'd like to see them fit more as standard on all models (2GB top range 1GB basic model), but that's just day dreaming.
Give me the rest I asked for and I'm a happy man.
Apple's Next Pro Mac