[julia-users] planned array changes

[harven]

I see that there are many changes scheduled for arrays in the next release. 
Can someone summarize what is planned?

I understand that [,] will become non concatenating. What will be the type 
of expressions such as

      ["julia", [1, 1.0]]

Any,  union{AbstractString, Array{Float64}}?

Will the following code return an error or an array of some type?

      push!(["one", [1, 5.1]], 1.5)

Is there some syntactic sugar planned for Any arrays, in the spirit of {}?