The timing of this withdrawal seems to fully indicate that the politicians involved have just tried to flush out their opposition and force them to play their

The timing of this withdrawal seems to fully indicate that the politicians involved have just tried to flush out their opposition and force them to play their hand. Now Reddit, Wikipedia et al. will go dark, but they will not generate the support they could have if SOPA was still under debate. Now when someone sends a letter to their local politician, that politician will just send an automatic reply of "This isn't as issue, we're not even debating this right now, I don't know what you're talking about.", further confusing the public. This is just a delay tactic being used to crush the groundswell around the current SOPA/PIPA bills. They'll come back when all opposition has faded away to a distant memory. Plus it gives the politicians who were involved plausible deniability on both sides; they're not dropping it, but they're not currently pursuing the matter either.