Online is simply the way people play now. Consoles aren't islands anymore. Every PS3 is online enabled and connecting them is easy. Completing a game is only the start: there are new weapons, levels and other items to download, but the reql future is a world where every game is played out online. I'm not talking about vanilla death matches either. Imagine Uncharted: Drakes Fortune with an online co-op mode...
As more games join the online band wagon it's becoming harder for offline-only titles to compete. Where it gets more excitin is in creativity, developers will have to be resourceful. Lookat Kane & |Lynch's treasury-fuelled bank robberies. Now apply that intuition to Uncharted and imagine you against rival teams rriading tombs and fighting through to the escape plane laden with treasures! Or try this for size, Assassins Creed; as competing hitmen struggle to locate targets. The online adventure hasn't even begun yet. Mutliple shooters and just the starting pistols, the best is yet to come.
God of War, Oblivion, Resident Evil 4, Uncharted... all classics but none of them have online modes. I acknowlegde, done right, as with Call of Duty 4's brilliant system and Splinter Cell's spy vs merc scenarios, their online abilities compliment and add value to the game. But, these games are the exceptions. More often than not, online functionalities are a half completed addition just to put on the back of the box becuase everyone else is trying it. Unless your offering something new to the already overcorwded party dont waste our time!
My real issue is with those who hammer at the weakness of some titles despite a brilliant single player game. How could Uncharted have been improved by online play, the shooting was beautiful because is was intwined with the elegat storyline. But, played with generically skinned pirates it would feel like cold, damp and thinning mountain air. Online can be a bonus, but don't over look those games without it becuase you'll be missing out.