is it possible now to look (search) (surf) for references on the Web directly from inside ZBrush ?
Not at this time. However, you can easily do so in your web browser and leave the browser window open behind ZBrush. ZBrush 4R6 introduced a see-through feature that allows you to make the interface partially transparent so that you can see whatever references you’ve found on the web without even needing to bring them into ZBrush. You’ll find it in the right portion of the title bar.