Recently I acquired a new MacBook Pro (2.4GHz, 2GB RAM, 200 GB HDD, 256 MB Nvidia 8600M GT). And switching from my MacBook (Tiger) to the new machine could not have been easier. Leopard's Migration Assistant asked me to run the MacBook in Firewire mode, hook up a firewire cable between the two and 'boom', in 30 minutes all my data and settings were moved over - INCLUDING APPLICATIONS like Thunderbird, Firefox and others. I clicked on Thunderbird, entered my password and had my corporate email going without ANY EFFORT!
Only glitch was the need to reinstall our Cisco VPN client because it seemed to be binded to the old machine's network adapters (or something like that!).
You can call that a serious saving of time and heartburn! Less than 1 hour to switch to a new machine - from start to finish. The migration of applications was much faster than having to install them one by one and configuring them to my settings. Kudos to the Migration Assistant team of Leopard.
And the best part will be the ability to use Time Machine to backup my data everyday - automatically. I and others in the company who travel a bit have seen laptops suffer catastrophic failures at the worst time. Recently we spent a few thousand dollars to retrieve data from a failed hard disk.