@TekNicTerror They are not just testing new options, they are testing new focuses for Talents.
Almost all the previous options were about Vertical upticks in Stats, either Set Stats (Str, Dex, etc...) or Calculated Stats (Mana, HPs, Endurance) with a few special abilities mixed in, that had to be much more powerful to equate to the other Vertical Progression Scheme.
The new scheme involves Talents that are purely focused on small utility tweaks to things, generally geared towards specific combat build types. They add utility, but can do so in much smaller amounts because they aren't competing for the obvious Min/Maxer Vertical Progression options on the grid. The two sets of Talents DO NOT FIT on the same grid together.
The other thing that keeps them from temporarily expanding out the Talent Tree Grid is the fact that part of the whole Talent concept is plotting how you are going to spend your talent points with the specific number of selections availabe. Expanding the Tree, even temporarily, would skew the resulting data that the Devs want to get. If you combined both these sets of Talents onto 1 grid, your Min/Maxers would go for the Vertical Progression choices every single time, while your more role-play heavy, utility enjoying players, like say @spoletta would have a real hard time picking the Talents they really want, because they still want to remain at least competitive with the other players, and so they would end up spending most of their points on the Vertical Progression options, even though those aren't the options they want.