Node.js is in great hands with Isaac. Unlike many other web/network platforms node doesn't go around gobbling up everything into core. The community behind node is stronger and contributes more than I've seen before. Focusing on that third party module system experience is a good move to further grow the community, one that Isaac has been heading for a while.
While many people will see the BDFL stepping down from a project as a bad sign, I think its the opposite. It has a dedicated and invested company behind it (Joyent), it's core doesn't try to do too much, it has legs of its own strong enough and it's community fault tolerant enough to grow quickly without him.
Ryan spawned a project that grew a community that in the long run isn't reliant on him, a rare achievement of platform/language creators.