stop giving out wrong info its 7:01:58.73123am ..... but on the real note, probably not for a long while as it has just happened a little over a month ago, so make the most of selling links on your PR10 sites, before they drop to 9 or 8.
Can be as early as Feb. or as late as whenever they really feel like rolling out another toolbar update. I can personally care less when they do it.
PR updates are like women, unpredictable and often change their minds Don't try to understand them, just accept what you get.
The next PR update will happen when no one cares... So to answer the question this most recent update was the last one.