I'll open this with a brief look at how I see things with Incarna playing out, followed by a game mechanic suggestion that I think is pretty interesting.
Allowing people to walk as personal avatars seems like a natural step for Eve. After all these skills and ships and grinds it would be very refreshing to wander a bar, stroll an on-station arboretum, etc.
I think the general community concern is that it would draw people away from the space game. To be realistic, it is unlikely a first version of Incarna will have enough out-of-ship content to keep someone interested throughout the play experience. There were be social gatherings, the RP'ers will flock there, there may be an in-station manufacturing and sales addition to the market. There might be simple games of chance. I imagine there will be the ability to walk in your own docking bay and observe your favorite ship directly.
It will be a fun distraction. It will be a fad that passes, perhaps a bridge in the mind of the average player between the current state of the game and one supplemented by Dust 514.As a game mechanic, it is money in the bank, in my opinion. When a friend recommends a game like Eve to someone who is not a gaming veteran, one question that invariably pops up is whether you can get out of your ship and walk around, and I know a number of people who have avoided Eve for that simple fact: you are a ship, not a person. With that hurdle covered, it becomes a lot easier to get your friends on board, even if that aspect of the game is a bit lackluster.
The other possibility is that it rocks. It is THE place to be, some bars become suited to certain types. An enforced RP might be good, in that certain in-person locations are the only places to reach specific contacts. And lets not forget the camaraderie of sitting around a long table with all your corpmates.
In the Eve novel The Empyrian Age (let's forget that Burning Life ever existed) we find a character who runs multiple clones. It is a unique ability, not common. I say incorporate a function like that for Incarna. Let's face it; most of our time in Eve is spent idle, autopiloting systems, mining, etc. Yes, some pvpers hop online get right down to it without a moment of attention to spare, but my suggestion is this:
As we fly in our pods controlling our ships on our regular tasks, impart a portion of our conciousness to controling a second clone in the social nexus of our choice, in Incarna mode. We have a tab like normal menu options that lets us check in on our avatar, read the local convos, order a drink as that last bit of mineral is loaded. It wouldn't be uncommon for a conversation to be cut short as the clone's counterpart's ship is attacked. Consciousness is shifted fully back to the pilot instead of continuing divided in half. The social aspect would be in a resizeable window that you can pin in a corner or make semi-transparent so you don't get distracted from that probing enemy in 0.0.
I see how this flies in the face of established cannon, but its a game mechanic that would keep every ship in the sky while also opening a new comm channel of sorts for the lonely pilots in their mining belts, a way to remind themselves that there are other people out there.
Running two clones? Crazy, I know, but from an 'everybody wins' standpoint it's not half bad.