There are buildings and you can build them, there are soldiers but they don't do damage yet (which means that once they start fighting, they will never stop, because they don't die)
And there are really too many weird bugs (especially with soldiers) to release a public demo without getting a whole flood of complaints.
Worse yet, we (me and JBSnorro) don't have much time now, so progress is slow.
In the mean time you can have a look at
the TKE scripting page to see how the new/extra mission scripts work (and you can make suggestions, of course)