Google's new innovation of imbedding GoogleTalk into their webmail interface is only beneficial. Honestly, it can't be any more prying than before, when GoogleTalk was a separate application. It's only more convenient for those who like the client. You don't have to use it if you don't want to. And, just like with personalized search, you can turn off the chat logging any time you want.
I personally think that Google's gotta be the smartest company out there. I mean--they don't have annoying popup ads and big banners all over their sites. Honestly, go to an online dictionary or encyclopedia (except wikipedia) or an online newspaper. They're littered with ads and banners all over the site. You can barely read what you're interested in because there are ads for online dating forums and other garbage. Google's ads are small, out-of-the-way, and they're exactly what you're interested in, since they're based on the content of the page. How can you complain about that? And 2.6 GB of free email space?
Read more at mail.google.com/mail/