thats pure FUD auto-sensing means it detects whether its 10 or 100 Mbps.No, you can get network interfaces that can send/receive on the same pins and hence can be connected together without crossover cables. Macs have had that functionality for years, and it looks like Sony have put a NIC in the PS3 that will do it as well. A quick look on Wikipedia shows the following:
It would have to be a crossover ethernet cable otherwise your out data would be coming in on your out data pin (so it won't work)
Looks like it's part of the gigabit ethernet standard.