Welcome back!
The most game-changing in-world improvement, I think, was the introduction and the following widespread of mesh - Second Life looks beautiful now, however, to stay competitive on the creators market, one has to learn much more than working with prims, because prim items and system layer clothes fail any possible competition. You may want to update the wardrobe - it's worth it. Mesh is beautiful.
Shopping events are the residents' favourite pastime now - those are basically where many brands rent a booth and offer no more than a few items at the moment of time, so residents can get acquainted with many apparel brands at one location. Very convenient. New ones appear every other month. Second Life Destination Guide has the separate category for those since very recently.
The number of active users is on decline, rarely going higher than 50,000 users loggen on at the same time in-world. The Grid looks barren, the regions are empty most of the time. Adult regions do not seem to have that problem.
The new CEO, Ebbe Altberg, strives for receiving the regular feedback from the users, answering to their questions as frequently as once in 2-3 months at the events such as LabChat and SLB Community Celebration. His aspiration for the consistent dilogue with the users is inspiring. Look up LabChat on YouTube to get the idea.
Good luck exploring the brand new Grid!