Hello I am the one working on the Watermint game engine,
First off its awesome to see that someone is taking some interest into my engine. For any criticism anyone has on the engine, I'm 16 and coding is my hobby, I'm not an artist by any stretch so don't expect to much on that department unless I can find someone to help me, although I will try my hardest to produce reasonably acceptable artwork. These data files are not to be used necessarily by them selfs but more of to give others a decent base to work off of. I will work to create artwork for menus, weapons, maps, and players as needed in the engine but not to directly replace the Quake3 data files.
I have no official "release" date because the engine will be worked on constantly. I will continue to add features and fix things. if anyone wants to give suggestions or ideas I'm open to all of it, just contact me.
Hopefully soon I will be able to update my website and if there are slows in progress it is due to schoolwork.
Also the "Mecwerks" engine no longer exists, all of my development is currently in Watermint/Spearmint/ioquake3.