Nice output for dataframes etc. will take a little while still (basically until we can prepare rendering methods for those types and push them to the relevant packages).
By awhile you mean, not any time soon. There's a Base issue that really needs to be resolved here. A lot of the packages, like DataFrames, have developers which aren't using Juno. Putting the rendering methods in DataFrames would mean they would have to pick up Juno.jl as a dependency, and everyone seems to get their panties in a bunch over adding dependencies that they don't specifically care about. However, "conditional dependencies", i.e. "Package A doesn't require that everyone have Package B install, but if it is installed, then we can add ..." don't truly exist in Julia right now, and the current methods for handling them have rough edges (indeed the upgrade to v0.5
using Atom problem stems from Requires.jl and conditional dependencies messing with precompilation).
Thus you probably won't be seeing this functionality entering DataFrames.jl because they might not accept the dependency, but Juno.jl might not want DataFrames.jl to be a dependency, so this functionality would exist...? One way to handle this is to have separate packages like DataFrameRendering.jl and you'd do
using DataFrame, DataFrameRendering and it would render properly. However, that is not a good user experience, so the real fix has to come from Base (and it is being worked on).
That's a long answer.