Phrases that would be similar to "Tip of the Iceberg" but with a positive connotation

Solution 1:

I don't perceive "tip of the iceberg" as negative. However, as onomatomaniak comments, in your paragraph this metaphor mixes rather inharmoniously with the metaphor "whole new wave".

The phrase "leading edge" doesn't mean the same thing as "tip of the iceberg"; "leading edge" has a connotation of newness that "tip of the iceberg" does not. However, "leading edge" fits your intended meaning very well, and combines meaningfully with the "wave" metaphor.

Solution 2:

How about 'only begin to scratch the surface'?

Solution 3:

I believe these applications herald a whole new wave of personal robotics applications.

Solution 4:

I believe these applications are just the forerunners of a whole new wave of personal robotics applications.