Hard Drives
It's hard to compare the hard drives in the two systems. Sony hasn't specified a size, and probably won't until they get far enough down the track that they can pick a number that's enough bigger than Microsoft's to be impressive, but they can actually put in without it getting too expensive. What they HAVE specified, however is that they're using a laptop standard 2" inch drive. This is unfortunate in a way. These drives are relatively bulky for a piece of consumer electronics. But more importantly, they're quite easy to get. Sony could find themselves in the same position as Microsoft, with hacked consoles with large replaced Hard Drives filled with pirated software.
Microsoft has chosen to go the other way this time. Probably because we suggested it. We're very influential. The Xbox 360 hard drive has not been specified exactly, but we DO know it's a 20 gig hard drive, we know it's removable, and from the position it's removed from, we do know it appears to not be very big at all. That probably suggests a 20 gig 1.8 inch drive from someone like Hitachi. This is the same type of drive used in iPod systems, so clearly (considering the screen and interface aren't needed) very small technology could be built around the drive. Unfortunately these drives are rather expensive, and would account for a very large percentage of cost of the unit. It's possible then that they're actually using a 2" inch drive as well, but we can't see clearly.
Communication
The networking of the two consoles is far more comparable. They both support standard Ethernet protocols and connections. They both support wired networking, and they both support wireless networking. Unfortunately while the PS3 includes wireless networking hardware built in, it will be an added accessory for the 360. It's hard to tell how many people will care. Many people prefer wired networks, and already have one set up for their current Xbox, and others possibly prefer a non-built-in (and therefore upgradeable) solution.
For the record, Microsoft actually has a wireless networking connection for the current Xbox, but it's not available in Australia. Bastards.
Another aspect of the Sony system that is a little above the standard set on the 360 is Bluetooth support. The PS3 uses Bluetooth as it's format of choice for the controllers. It's probable that the Bluetooth support will also extend to other relevant technologies such as mobile phones, PDA syncing etc. What the hell they'll do with that, who knows, but they have it, so they can.
The Xbox 360, just for completion, uses high speed RF for it's controller connections, and that's not really going to be used for communicating with anything else. RF isn't really inferior to Bluetooth in any way, and they're both entirely reasonable ways to connect wirelessly. Bluetooth is just a bit cooler, as well as more versatile.
We are a little disappointed in the number of controllers, though. The PS3 can support up to 7, which is pretty cool, while the Xbox 360 can only support the current 4. 7 controllers is nice, but 8 would have been a far more useful number. Sports games especially would benefit from 4 on 4 play. Though that being said, a 7 player game like Mashed, PowerStone, or Fusion Frenzy would be a true joy.
It's nice to see Sony joining the party, and in such a big way. Putting only two controller ports on the PS2 was almost unforgivable, considering every other console since the N64 has had 4, and MultiTap is a very inelegant solution to what should never have been a problem.