Kotaku
I have no idea what the source of this chart is, but glancing at the most current numbers it seems pretty accurate to me. (If you know the source, email me and I'll gladly update this post.)
While the dominance of World of Warcraft is unsurprising, it does look like its never-ending ascendancy may be slowing. The popular Lineage is taking a dive, nearly on par with its sequel, which for about a year was exceeding its player base. (I wonder what caused all those people to come back to Lineage in the last year?)
Can that many people be playing RuneScape? Their website says they've got 70k people or so playing right now, so I suppose a three-quarters of a million subscribers is possible, but I'd never even heard of it. Maybe we know the source of this chart after all: RuneScapes' savvy marketing team. (Thanks, Llama3!)
Update: Thanks to everybody who pointed out the source of this chart, the very fine MMOGChart.com.
