I have only skimmed through the docs myself, and I like that advantage/disavantage die idea as well, it could easily be incorporated into Novus as a flavorful add-on (i.e. roll 3d10, advantage = take best 2, disadvantage = take worst 2), and still allow for exploding/imploding of dice as per normal..
What is funny is that a few days ago (before I got the 5e Playtest materials), I was talking to somebody and came up with an alternative method of using/playing Novus -- No actual skills, just pips of specialization, with all rolls being handled via Saving Throws (or opposed Saves for Combat). The pips of specialization would apply to ANY roll that was associated with the specialization, regardless of the stat that the roll required...
For example -- +3 Locksmith == getting +3 to all Saves relating to Locks.... trying to figure out how to open a lock, that might be wisdom, actually trying to pick the lock might be Dex, lock lore would be Int, and all would get that +3 when a roll was called for...
And for a little bit there, I almost thought that D&D 5e might be doing things in a similar manner... But I don't think it is... It seems as if they are only giving skills as part of one or more types of package (Backgrounds for sure, but also via Themes), so I am unsure how one might improve in those skills, since there is nothing that says improvement is possible, nor is there anything regarding these Background/Theme packages and how they may possibly work...