Nothing much has happened during the last two years. They're still more or less round, they always seem to grow up first and then out, which makes them look weird from time to time. But they seem to be content with their place (still all three in the same pot I sowed them in) on the west facing window sill.
Now I took a closer look again and I saw this:
Euphorbia obesa flower bud on April 10, 2011
The Euphorbias are four years old now but I wasn't expecting them to flower just yet. The bud is still closed so I cannot say yet, if it's male or female. And so far it's only one flower, I don't see any indication for more flowers building or for any of the other two Euphorbias flowering.
Euphorbia obesa on April 10, 2011