what I'll miss in this version?

It sounds very interesting that very soon, we will have the new, responsive version, but i think it will be easier to help our decision, if we can know the major differences in function compared to the existing version.
Questions, simple and clean:
1.I’ll Lose some functions and what?
2.Will you continue to develop the old version and the new or the old will stop very soon be supported?

thank you!