After about four years with Adsense, I, too, received the standard termination email. I deserved it. While working on a new website, and maintaining an increasingly effective (and relevant) blog, I also allowed to remain a network of 'junk sites' with modest traffic fuelled mostly by some Adwords arbitrage. I should have turned the junk sites off and stopped the arbitrage as the revenues were truly infintesmal in the total business sense. (Enough to get a cheque from Adsense in the lower range of eligibility every month or two.)
We earn most of our revenue from print advertising, and that business is doing well.
The Adsense account operated on a separate user id than my Adwords and blogger accounts; this also relates to the practice about four years ago when Google didn't mind and sometimes encouraged separate accounts. Shortly after receiving the termination email and filing my appeal, I noticed that all email communciation with the terminated account had ended, while the Adsense account on my now-primary user id remains in place.
Although I could presumably use Adsense on the live account, I'm going to hold off until the site rebuild is completed, and its compliance with all Google policies are confirmed. Then I will seek clarification and confirmation from Google that all is right before proceeding (and I will watch Google policies carefully to ensure compliance both in spirit and practice.)
The point I'm noticing is that the wording in the Google email explaining termination because of significant risk to adwords advertisers is NOT the same as the banning for invalid clicks, and there doesn't seem to be any indication that banning for this reason means a "ban for life". In the case of click fraud and overt abuse, the lifetime ban makes absolute sense -- in the other situation, the argument must relate more closely to the integrity and practical application of the individual Adsense user.
Of course, in many cases, the ban will indeed be a lifetime ban -- publishers splitting hairs, providing borderline content, or gaming the system in a manner that really causes problems for Adwords advertisers aren't going to get back in just by tweaking things a little. But I sense we will see many more resurrections in the months ahead. In my case, the modest income loss will be offsest by the lessons learned here; and a true appreciation that Google is doing all it can to make things right within the content network, something that all legitimate publishers should appreciate.