A few thoughts on all of this:
First, Fred, thank you for all your hard work compiling this information. It is something I've been meaning to take a look at for a while, but haven't had time.
I think these results are absolutely outrageous, in several respects. First, it is ridiculous that Prosper still hasn't served (or at least hasn't filed proof of service) in so many cases. There are extensive computer databases readily available for tracking people down (especially since Prosper has a wealth of information about borrowers, including full names, social security numbers, dates of birth, copies of drivers' licenses, etc.). If dilligent efforts at personal service fail, you can use substitute service (leaving a copy at the person's home, place of business, or place where they usually receive mail (except a USPS PO Box) with an adult and mailing a copy there as well. If that fails, as xraider noted you can seek court permission to serve by publication.
Second, what is up with all of the dismissals? While it is possible some of these reflect settlements, Prosper absolutely should be telling us if that is the case. Certainly it is equally plausible that some of these dismissals were due to ID-theft, in which case Prosper is legally obligated to repurchase the loans from the lenders.
Third, Prosper's lawyers certainly seem to make an inordinate number of paperwork errors resulting in documents being rejected by the clerk. While some clerks have idiosyncratic policies, the number of rejections seem extremely high to me, especially since Hunt & Henriques is supposed to be an excellent collections firm, and the types of documents that are being rejected (especially requests for defaults/default judgments) are the bread and butter of collections cases (where debtors often fail to respond to the complaint). They should have this process down to a science.
The bottom line is (as Fred states) that the NAT results so far do not appear to be encouraging. Prosper MUST provide lenders (or at least those lenders opting-in to the NAT) substantial information about the progress of these cases. It should have created a page on its website listing all of the NAT loans, and the current status of each.