Just to clarify the add-ons situation for everyone:
There is an entirely new add-ons system in V9 which means that add-ons are self-contained in their own .zip file, and you just plonk them into your add-ons folder without having to extract them and all that jazz. There are lots of requirements with regards to certain files you need in your zip, and naming conventions to follow, to make sure that your add-on will be accepted by the V9 add-on system. All of those will be clarified with the release of V9 I expect.
RTB 2.0
One of our main features in RTB 2.0 is the Mod Manager which works in tandem with an online mod database. So you'll be able to go on the rtb forums, submit a mod into the system and specify a title, description, icon etc. and then people ingame will be able to browse the mod database, comment and rate the mods, and then download and install them into their game without ever having to close Blockland. You can see where the advantages lie here. The RTB System will then notify you of new updates for any mods you have, and give you the choice to download and install etc.
There will be a much more in-depth informational pack on all the RTB 2.0 stuff when V9 gets closer to its release date.