I really wish that Google would integrate a bunch of their services into a single interface, but it doesn’t look like that will be happening anytime soon. Some of their services, such as Google Notebook and Google Reader, would feel pretty natural if they were part of the Gmail interface.
A good example of how it would work can be found in this Gmail + Reader Integrator Greasemonkey script. Once you install the script there will be a new section in the sidebar that lists off all of the feeds, with unread feeds in bold. The reading area for your feeds is located underneath the emails in your Inbox, which can be a little annoying if you have a lot of emails in your Inbox. Unfortunately there is no way to collapse your Inbox. :(
There are a handful of settings that can be configured as pointed out by the developer:
You can change the height of the Gmail thread list and the embedded reader by modifying the values in about:config (filter by ‘reader’). You can also revert to the old behaviour of not expanding the folders in the feed list by setting expandFolder in about:config.
The only disappointing thing is that this script is only available for Firefox, and not nearly as nice as it would be if Google had their own system available.