Case for a click fraud service?

Yes it is both feasible and has been done by a few companies:
AdWatcher
AlchemistMedia
AuthentiClick
Benchmarktracking
ClickAssurance
ClickDefense
ClickDetective
ClickFacts
ClickLab
ClickRisk
ClickScoring
ClickSentinel
Datashaping
Greenlight
Nami Media
PPCTrax
TrackingROI
ValidClick
VeriClix
VisitLab
Whosclickingwho
FightClickFraud
BogusClick
ClickFraud

Some are out of business; some are emerging; some don't say a lot on their sites, while others are always seeking and getting media attention. I have personally tried Whosclickingwho and Vericlix, the former for 14 months on behalf of a former client.

It is not clear whether you are asking for the internal logs of the advertiser, the PPC search engine, or a third-party click fraud detection service. I can speak for the last item.

I am mentoring a friend in the US who is building Visitlab and one of its many innovations is to expose the user's data in its native MySQL format by allowing the user to get to it using something like phpMyAdmin.  You can't ask for more complete data.  I haven't personally tested that, but it's a listed feature. Another innovation is to create a limited privilege login for others, such as a rep from the PPCSE, should they care to log in and view the reports for themselves.  The usual data download options in zip, csv or txt format are also available.

As an advertiser, I don't want to do "research": I just want to be told if various conditions are met and therefore represent suspicious clicks. I can then log into my Adwords account to see if the number of clicks is within 10% of the clicks noted by the reporting service.  When this reaches the point that it is worth my time to argue with Google, I would like to be armed with the third party data and my own server logs (few other advertisers would know how to get the latter).

I am using multiple click fraud services to track my own ad campaigns and I sometimes find that a click is picked up by one and not another - this is perplexing but a fact. What is more interesting is that Google is not charging me for multiple clicks from the same IP address - not even the first click. This says that the simpler forms of questionable clicks are no longer an issue, at least in my case, and that the real challenge for PPCSEs is to determine if a single click is genuine or fraudulent.