Apple has specifically named: "Droid, Droid 2, Droid X, Cliq, Cliq XT, BackFlip, Devour A555, Devour i1, and Charm.1," all Android phones, as specifically infringing Apple's patents.
Apple has not sued Google directly because they are not selling Android directly... and Android itself is not, apparently, at this point directly infringing any Apple patents. The PHONES however are. It remains to be seen when Apple may file against Google in some kind of inducement to infringe suit because Android enables Android devices to use Apple patented devices and technology, but that is probably a legal stretch.
However, Oracle has sued Google over Sun's Java code found verbatim in Android's code base... apparently without license. This may be another SCO moment, but only the courts will determine that.
Several of the Apple patents in the lawsuits have to do with things that will heavily impact Android phones look and feel... and operation as multi-touch screen phone operations. Apple has also filed a patent lawsuit against HTC for similar infringements on their Android phones. I hear others are in the works against all other Android phone makers.
In the two year run-up of iPhone/iPad development before the iPhone release, Apple submitted over 200 patent applications and those are now being granted almost daily. Now that Apple is receiving the legal ammunition of those official patents, they will be going after those companies using their intellectual property. Steve Jobs promised that when they introduced the iPhone in January 2007... and they are following through.
I would add, they are pretty poor knockoffs.