I hope it does not also cause anyone to miss those negative reviews that have horrible writing errors and flawed arguments. Those can sometimes help the product maker.
I am not connected to the company selling these in any way other than I think I may have purchased something from them once.
Phishing types are already preparing false communications and false sites with such warnings "from google". There are certainly many mechanisms in existence to help authenticate that a communication is actually from google. Hopefully the use of such mechanisms is clever enough to avoid more contamination.
I welcome versions of Cyanogen without the google applications.
CommuniGate Pro is not FOSS and my opinion is biased as I have business interest in this platform. However I do believe it is the best solution to this problem and many others despite not being "Free". It is available on most any platform you would want to run it on, supports Linux (not just specific distros) and has implemented enough RFCs to be regarded as a comprehensive communications operating system. The Flash client "Pronto!" has IM auto-archive. There is a PKI built in permitting the actual storage of the archives to be automatically encrypted by the rules engine on the storage device.
Stored message encryption
Pronto! Flash client
http://talktoip.com/ (use sign-up link to get a full running demo account)