The recently launched Google Mobile Interstitial penalty has been generally well received by users, as the experience can be quite the nuisance. For sites that have been penalized the way to recovery is to remove the interstitial and let Google crawl the page. Once it has been re-crawled and indexed the penalty will be removed in real time.
Google has been testing and changing their Ad display for years and this most recent test seems to be the closest to an Ad not looking like an Ad in recent memory. With an outline instead of color block, quick glances make it appear nearly like an organic result. Time will tell if this becomes what we see for all Ads going forward.
The Google Webmaster blog offered up tips on how to help webmasters deal with user generated spam in on websites and forums. Tips include: 1) blocking or disabling suspicious behavior, comments and spammy terms 2) make use of moderation with both automated and manual systems on a frequent basis 3) Disallow anonymous content and make use of Captchas, as well using nofollow for links in the comment field. These are all good guidelines to use and take note of.