Kiva Zip eliminates the intermediaries directly connecting lender and borrower in person to person microlending. This will reduce interest rates for the borrowers (which during the initial testing phase of Kiva Zip pay 0% interest). The use of direct electronic and/or mobile payments further reduce the costs of the loan transactions.
On the other hand Kiva expects that these loans carry increased risks for lenders.
Kiva Zip is in pilot stage. Here is what Kiva says about it:
Kiva Zip is testing new ways of realizing this mission with the goal of expanding our reach to unserved populations by using new technologies that also drive down costs to the borrower. …
We are excited to begin this first Kiva Zip pilot, and we know that there will be a number of other smaller trials and experiments on the Kiva Zip website. For example, there are plans for borrowers on Kiva Zip to be able to make comments and updates directly on their own loans; different loan sizes might be explored, or displaying loan amounts in Kenyan Shillings; and the look and feel of borrower profiles will differ from those on Kiva.org. It is our hope that many of these experiments will prove successful, and we will be able to apply our learnings to Kiva.org to continue to deliver the best experience and outcome for all lenders and borrowers.
On a sidenote: Zidisha (see recent coverage) is already using the direct p2p microfinance model (with interest for lenders).
(Kiva Zip mentioned at around 08:30)