My first exposure to online gaming didn't begin in a lobby waiting for the server to auto-balance teams while various accents chatted out of my surround sound system. It was with my neighbor across the street, staring at the DOS setup screen for Doom 2, while shooing away our parents from picking up the telephone. How we play with/against one another has come a long long way. Looking back at the last two years, (as opposed to the last 20 in the aforementioned example) online gaming has evolved into a melting pot of shared entertainment. Recently, developers have expanded into cross-platform gaming (Portal 2), server-side game streaming (OnLive), and of course, world-wide ecologies that are even studied by scientists.
Online gaming is now more than just a connection, a session, and a scoreboard. Developers have experimented with physical proximity (3DS' street pass in which you passively exchange character or items, or Google's Ingress, an augmented reality, social game with emphasis on defending and conquering real-world landmarks). Social gaming isn't just expanding, in some cases it's stripping down the way we interact with one another: Journey for PS3, an award-winning game where mute players communicate only through gestures and actions, limits communication and identity for an atmosphere spiritual-like experience. And then there are experiences like Star Fox 3D for 3DS, that utilizes the face cam to show the expression of the player as his/her ship blows up.
Online gaming is such a melting pot of experience nowadays that even in-browser gaming has taken a foothold of lunch breaks without monthly fees and in most cases completely free. Take a look at the popular 3D MMORPG Runescape (said to have over 130 million accounts and growing). Even online gambling, considered to be the first online gaming experience, has taken a page from communities with regards to safety, accessibility, and entertainment. A plethora of free, various online experiences are just one Google search away.