In the end, everybody was able to connect to any MP game, even when it used DLC. We like to think the theory behind this was actually pretty cool it achieved its goal of avoiding the split.
To give an example, a lite tank would have low quality textures and compressed sound effects for those people who did not own the DLC. In this lite data, the fidelity of the artwork, audio and animations was lowered via compression techniques. In the form of so-called 'lite' data, we released downloadable content to everyone who owned the game, regardless of whether people purchased it.
If you've played Arma 2, you may know that we already provided a solution to avoid this type of split.