I can see how you can put online to good use when not playing your typical multiplayer game after reading bkillian and Silent Buddha's post. I also agree with RancidLunchmeat that online doesn't necessitate multiplayer at all, given how many players don't play other than your popular online game.Not to harp on SimCity, but I really don't think that should be looked at as an exemplar of why cloud offload is a good idea.
SimCity's server-side simulation is composed predominantly of simple numeric message passing and mailboxes, with player-generated updates coming at a frequency of 3-20 minutes, with global visibility taking tens of minutes to hours to days, if ever. This does assume that there isn't a hiccup in the data used when it gets to the client or how it is evaluated by the validation server, whereupon it may just roll back hours of your progress or permanently glitch the city.
The vast majority of the regional simulation as the player sees it is actually an array of nearest-neighbor data that the client requests and proceeds to run its own simulation on, not the cloud.
There are just way too many clients relative to the number of servers to think that having them do any simulation work is a net win.
The complexity and latency of this method is the modern-day play by e-mail, except this ISP is allowed to drop and delay emails and decide on its own if your client has played the game the wrong way.
I haven't followed PA, but my impression was that this was a client-server game with a predominantly multiplayer focus. The server wasn't indicated as being in the cloud, but a specific dedicated machine that could also be the same machine as a player client.
My point when I say I can't understand why a console forces you to play online, is that it goes against the typical philosophy in the design of a console.
Consoles are historically meant to be plug & play machines, insert your game and play. Having to set up a connection in order to play certainly doesn't apply here.