I updated my flex builder version from 3 to 4, i was creating a project on which I used the TileList component, but now I can't find it anymore on the new components panel, does it still exist on the new version or it has been deleted or replaced with another component?
TileList can still be used but you need to manually include it in the source, the new list component seems to be its replacement and you can use layouts to define its behaviour.
The Spark List (with layout set to TileLayout) is a replacement for TileList. But you can still get to TileList in the Components panel. Uncheck "Only Show Recommended Components" in the panel options menu to see all components.