It's a nice thought...but every time someone tries to make a be-all DAW...it usually sucks....plus, you then have no options, either you use it all or you move to something else.
I like that Toontrack is mainly focused on the drums. I know they also have EZKeys...but it's not anything like SD2 or SD3 on the drum side.
I EZKeys is more like EZDrummer...a nice song starter setup, but that's it.
Anyway, I just think the drum stuff will do better if Toontrack sticks with them primarily.
Heck..there's already dozens and dozens of DAW options out there.