It’s reported on at ReadWriteWeb–they include some useful visuals and numbers:

There’s a lot to parse here, and the way to best define these categories is a thorny question. However, one of the most fascinating bits of information is that there are almost as many “creators” as “inactives” in 2008. This reaserch is pretty bullish on the growth of the truly participatory Web–in 2007 it has around twice as many “inactives” as “creators.” It’s only one report, but the idea of that gap closing over just a year is striking. On the other hand, “spectators” is far and away the most broadly applicable descriptor, and the only one to break 50%. Intense participation may be on the rise and non-participation may be on the decline, but the predominant mode of participation is still a form of consumption rather than production.

We’ll have to wait and see what the numbers look like this time next year.